Model 3's ride isn't worse because it doesn't have air suspension - it has low-cost, lower-quality, non-adaptive dampers, specified and priced so that they'll be "good enough" for a car that sells almost half a million units per year. And then they make you jack the air pressure in the tires up to 45 point jesus pounds per square inch. My FIL had an S 85 and it rode amazingly well on its steel-springs.
Air springs are generally on cars that ride well by default, big heavy long-wheelbase things, and so people seem to associate air ride with good ride - not so. See e.g., Lucid or countless other cars that ride great with steel springs and *good* damping and tuning. A taller wheel/tire that is less influenced by small bumps and dips can make a big difference too - S rides on a 1" larger diameter tire than Model 3, and that size difference is baked in, so that's a real difference you can't easily fix on Model 3 without other compromises.
But well-tuned adaptive dampers, or just a good high-quality damper, are the big difference. If Model 3 Performance gets adaptive dampers, but still has steel springs, I wouldn't be surprised if it has significantly better ride/handling balance than the base 3.