I frankly think folks like you live for the debate, as I've been through the same thing on Lexus forums as to if extended warranties are good or bad a zillion times over the years. The FACT is, there is no single answer that is good for everyone, and it's impossible to draw conclusions based on anything other than hope when it comes to Tesla because the brand is so new and there is no AFTER WARRANTY track record for the need of repairs. I'm happy you have made the decisions you have for yourself. They are not however my, and perhaps other's POV.
Reliability is very important to me when considering an auto brand. Unlike some owners, I prefer to keep my rides 6-8 years on average, but I also put a lower number of miles on them (implying I perhaps do far more errands getting in-and-out of my vehicle, than others that do with longer commutes and road trips). I also came from owning a Lexus Hybrid and a MBZ ICE to now my single MS, and I have remote family dependent on me to get there if problems were to arise -- so having my MS available and operational is an imperative. I'm a research hound and spent months looking into Tesla and MS before ordering this past September. Beyond the whole range anxiety thing I had to get over -- and isn't part of this discussion -- my greatest personal debate was if I could trust Tesla reliability and what it would likely cost me to own one for the whole time I have it in my garage -- especially for a vehicle that's base price cost me $40K more than each of the previous luxury brands I owned. I want to budget for the rides I own for their life, and I'm willing to perhaps pay a bit more than some by having an extended warranty if that is what it takes to hedge my bets with total cost of ownership. My personal experience has been I would never own a MBZ or BMW without a nearly bumper-to-bumper extended warranty. OTOH, having one on a Lexus is a more difficult decision as I've not had the same personal need for repairs on any of the Lexi I've owned -- some more than 8 years.
The net on Tesla MS reliability for me was (and is) there is no brand track record to give any true feeling of longer term reliability, so I think it's just a crap shoot what anyone says one way or the other. I do know that Tesla isn't Toyota where some decades old vehicles are still on the road that have had almost no work done to them of any consequence. Tesla does not have the recognized long-term reliability that I've experienced for more than 20 years with Lexus. Some well known luxury vehicles often compared to MS are just flat-out expensive to maintain as they age -- everyone reading this can fill-in their (typically German brand) names with examples they may know. Only the first MS are about to exit warranty, so there are no facts from decent 3rd-party surveys to speculate from, as there is with nearly every other auto manufacturer.
I consider it as only subjective input when one tries to compare the sort of failures owners have encountered during warranty and extrapolate that out to post-warranty. Using data from independent sources like True Delta, is still only using in-warranty data for MS. Comments and horror stories on forums like TMC are what they are, and may not perhaps be representative of the broader set of owners -- but, it's input for consideration just-the-same, especially when no other real data exists. I am uncomfortable extrapolating that my Tesla MS will be as reliable as say Lexus has proven itself to be over 5 models and 20 years of my ownership, along with generally acknowledged trade-recognized statistics... Elon's statements that recent MS (mine?) are more reliable, is just that -- a marketing statement -- not something with facts to back it up that sways me one way or the other.
While it also can be debated, I always look at terms and price a mfgr has for their extended warranty, and use that as an indicator -- right or wrong -- of the mfgr's confidence in their own vehicle in the post-warranty years. Along those lines, mfgrs like Lexus that offered 8-year extended warranty for $1600 with no deductible on my previous 2013 RX450h say something to me, whereas MBZ wouldn't offer more than 7-years at double that price, and my last BMW was also over-the-top price-wise, but had specific exclusions including all the components (motors, struts, etc) on my hardtop convertible -- which are probably the most mechanical part of that vehicle beyond the ICE. As I said, it's all just input, but it does say something to me ...just as Tesla does by making the change to their terms not allowing transfer and increasing price before the first MS ever makes a claim using an extended warranty and early owner may have purchased.
I have traded-in as many vehicles as I've sold on the open market before buying the next one. I would say that with my luxury BMW and MBZ, having the transferable extended warranty made a significant difference allowing me to sell quickly and achieve top of comparative private-party prices. It was a HUGE differentiator with my BMW that I got rid of because of ongoing reliability issues (but still felt OK selling it by providing all service records and it had another 6-years of coverage, even though it ended-up with a class action suit that was won a couple years after I let it go.)
For me though, I just don't yet have sufficient evidence Tesla has built a product that is designed for cost-effective long-term ownership like I want to enjoy, nor do I see Tesla taking actions that are evidence they care about anything other than selling new (and maybe CPO) cars. I hope I'm proven wrong. As you and others point out, a Tesla extended warranty isn't needed to deal with the power train ...but, just like all ICE vehicles, Tesla still has other gears, hinges, motors, switches, 12V battery, and loads of electronics perhaps beyond other competitive vehicles. With a single exception, none of my previous vehicles have ever had problems pre or post-warranty with the ICE and it's components -- it was always with all the other things that a MS has as well -- struts/hinges, electric windows, audio system, steering wheel and seat movement, auto-dimming mirrors, etc. Some failed during warranty, others in years 5-8 ...but that's just my personal 40+ years owning and experiencing Ford, Honda, Acura, Toyota, Lexus, MBZ and BMW -- and now Tesla.
To each their own with a decision on the value of an extended warranty. They don't have sufficient value for me with some manufacturers, but they do with others. As I said earlier, I'm sad for MS owners that didn't buy when they had the opportunity -- assuming they wanted to in the first place, but I am pleased I bought my contract with the transfer terms in-tact when I did.