The flash on your iPhone is nicer than cheaper embedded devices / microcontrollers. I have no idea what Echos use, but I’ve seen modern ARM micros have a 50k flash life expectancy or less.

It’s not impossible to have a flash memory without a user data eeprom that you could “burn out” (in reality make less reliable).

I have no idea if it’s true in this case, but the straight comparison / jump to iPhone 11 might also be speculative.