Same as the one earlier in the thread: Build servers, nicely loaded. A build generates a ridiculous amount of writes for stuff that just gets thrown out after the build.

We actually did try with SSDs about 15 years ago, and had a lot of dead SSDs in a very short time. After that we went for estimating data written, it's cheaper. While SSD durability increased a lot since then everything else got faster as well - so we'd have SSDs last a bit longer now (back then it was a weekly thing), but still nowhere near where it'd be a sensible thing to do.