While disappointing, its not surprising that the 3 and Y are getting more new tech - they were more specifically designed that way. The S and X were the first to come out, as a premium vehicle platform to entice folks with larger wallets into EVs. Now Tesla is more established, and is seeking a larger audience, incorporated a more advanced interface for the 3 and Y. Nothing unusual for the auto industry.
A new Honda Civic has better tech than a 5-year-old Accord, even though the Accord is a premium platform relative to the Civic. The difference, for me, is that I can add most of that tech to my 5-year-old Tesla S without having to buy another to do it.
The Mercedes will likely have superior materials, and better fit and finish, but they've practiced for over 100 years. As to the range of the EQS, no announced vehicle has meet the ratings the manufacturer hypes, whether Mercedes, GM, Ford, Polestar, etc...so I wouldn't hold your breath...and that doesn't take into account the battery range improvements Tesla incorporates on a constant basis, which will probably be the same or greater than the EQS's range by the time it is actually released.
A big advantage over Mercedes, IMO, is Tesla has been 100% vested in electric vehicles, battery design, and materials design (i.e., SpaceX) for over a decade now, where Mercedes and other legacy auto companies are only recently involved with larger production of EVs due to regulatory pressure and unavoidable shifts in the industry (propelled by companies like Tesla, Rivian, Lucid, etc.). Virtually every legacy EV announced has been plagued by software issues prior (and so far, after) release - something better craftsmanship won't fix. I'd rather be driving my Tesla than be towed in my EQS....but we'll have to see how that turns out...
