This is true. I also only have east/west roof, so that cuts my annual production down by about 1/3. This is made up for because I did the install myself, saving tens of thousands on labor costs.
None, nada, zilch on a well designed system. An occasional (and I mean very very occasional to rare) is all you need to clean the panels. In winter, it's just silly to try and clear the snow off. It's not worth the cost of having someone come to clean it, cause you won't make up for it in additional production. Nor is it worth me going up on an icy roof and breaking my neck myself. Plus once you get a sunny day (when there would actually be production anyway!), it melts below the snow, on top of the panel, first, causing all of the snow to slide right off. Sometimes you get some buildup on the bottom rows where it doesn't slide off the roof below it, but as long as you have a modern system (either micro inverters - see Enphase, or power optimizers - see SolarEdge) that can keep producing when some panels are shaded, it's no big deal.
As for replacing inverters (or panels) - my panels have a 20-30 year warranty, and my inverter I think is 10 or 15, that I paid a few hundred to get doubled. There are also power optimizers under each of the panels that could theoretically go bad too, but they're relatively simple (as opposed to micro-inverters), so it's unlikely they'll fail in that same timespan.
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@Garlan Garner and I have a SolarEdge based system, which is power optimizers under each panel that do a DC-to-DC conversion, that then feeds to a (simpler and more efficient) central inverter. The beauty of this design is that you get the per-panel benefits of micro-inverters (a small DC-to-AC conversion under each panel), with less electronics up on the roof, and DC in the central location where you can add in a battery system (PowerWall). The original Tesla inverter partner for PowerWall is, in fact, SolarEdge.