All cars looking the same is not unique to EV's. Been that way for a while.
But to answer a bit more deeply,
Go sit in / drive a model 3/x/y. Then go sit in /drive ANY other electric vehicle in the same price range on sale from an established auto maker. The differences are very apparent, particularly the way things are laid out, the finishes chosen and the actual finish work. Teslas are built on flash and "look at these doodads!" vs "can I easily adjust the AC or set the cruise control without having to take my eyes off the road". And if you're shelling out for something high-end like an EV, it better not be full of cheap plastic and vinyl and look like it was assembled by the last halfway sober dude on the line at 4:55 PM on Friday. In all of this, actual car makers have a lot more experience and skill at making it feel like a car. Yes, quality still varies and you can get individual bad examples (like Pontiac's Aztec). But when it's a consistent thing across all models from a given brand, you form opinions.
We tested Teslas when we were shopping for wifey's EV. They drive decent, lots of power and feel good. But they were not nice to be in. One step above a coach cabin on an airplane. It was a major deciding factor. Their subscription pricing model for things like autopilot and other features that are just included in the price from other makers was a turn-off as well. (And I know that's mostly Mercedes' fault, they started it).
These are my opinions, so grain of salt of course. But the "go try them before you decide" advice should be pretty universal.