Only the very cheapest phones still have eMMC. I bought a Pixel phone second hand last year and it shows the wear level of the storage somewhere in the settings. I forgot the number but it was so low, extrapolation got me to something crazy like maybe 20 or 50 years of expected use at that rate

That consumer rate isn't datacentre use, but not every task is write-to-persistent-storage intensive. You can also replace the sdcard and write to that instead if this is a worry (that's what I've been doing on my phones since I use them quite intensively; maybe that's overkill nowadays idk)