This I never understood. I have 3 different RPis running since they were available to buy. A 2, a 3 and a 4. All with the OS on microSD and no optimisation like writing log files to tmpfs or similar. It’s plain Ubuntu Server for ARM.

And in all these years, I had maybe one microSD going read-only on me. Cloned that to a fresh one, did an fsck and the Pi was up and running again. That’s it. No other issues despite various sudden power losses etc.

I don’t understand where these rumours about bad reliability of SD cards in Pis come from.