The problem is if you want a 4K tv from Sony, Samsung, LG, or Vizio you'd be hard pressed to find any that are not some variation of a "smart" tv. You could go back to 1080 and find some dumb TVs still but then you're losing out on the HDR support.

First of all, it's not obvious to most lay people. Second, I wouldn't have a problem if that was the reason stuff stopped working, but if Smart TV makers / sellers explicitly advertise certain apps, those apps damn well better have a decent life. I bought mine and days later my favorite Roku app (Spotify) decided to shut down that app for something like a year. Nothing to do with hardware advancements, they just made an intentional decision to de-prioritize a device I had already been sold and it didn't keep up.

Fair points and totally agree. I was dumb enough (I would use the same words!) to buy one the first time round so I agree with you.