Old OSes like MacOS 9 barely touch your disk with writes at all, they typically don't have any log files they're writing to, they barely use any virtual memory. These things are never going to see the terabytes of writes they're rated for.
Lots of people (me included) use SD card or Compact Flash adapters in old machines without wearing them out and those have way worse endurance than SSDs.
I have a PowerBook that's been running 24/7 for the past year as an Apple Internet Router and AppleShare file server on GlobalTalk off an SD card in a SCSI2SD adapter with no issues.
Lots of people (me included) use SD card or Compact Flash adapters in old machines without wearing them out and those have way worse endurance than SSDs.
I have a PowerBook that's been running 24/7 for the past year as an Apple Internet Router and AppleShare file server on GlobalTalk off an SD card in a SCSI2SD adapter with no issues.