@Axtremus said in Why *not* to use a SSD for Time Machine Backup:
Yes, mostly affect write speed, not so much on read speed
I would think that's not a major issue in backup, particularly if incremental, such as Time Machine.
Hybrid drive with smaller SSD + bigger HDD … for a while that’s the standard for iMacs. Even Apple stopped doing that now. I guess people just don’t want to deal with the mechanical failures of HDD’s moving parts.
My 2014 iMac has such a drive. It failed after about 3 years. I had it replaced. But, I'm currently booting from an external SSD and it works great. My Time Machine backup is to a 4TB RDHD.