> but enforcing a few percent extra helps.

Only if you fill the drive up to 95-99% and do this often. Otherwise it's just a cargo-cult.

> So while I would say to use a lower percentage as space increases

If your drive is over-provisioned (eg 960GB instead of 1024GB) then it's not needed. If not and you fill your drive to the full and just want to be sure then you need the size of the biggest write you would do plus some leeway, eg if you often write 20GB video files for whatever reason then 30-40GB would be more than enough. Leaving 100GB of 1TB drive is like buying a sneakers but not wearing them because they would wear.

Nah, we used some consumer SSD for write heavy but not all that precious data, and time to live was basically directly dependant on the space left free on device.

Of course, doesn't matter for desktop use as the spare on drive is enough, but still, if you have 24/7 write heavy loads, making sure it's all trimmed will noticably extend lifetime

My drive gets almost full relatively often.

> If your drive is over-provisioned (eg 960GB instead of 1024GB) then it's not needed.

I disagree. That much space isn't a ton when it comes to absorbing the wear of background writes. And normal use ends up with garbage sectors sprinkled around inflating your data size, which makes write amplification get really bad as you approach 100% utilization and have to GC more and more. 6% extra is in the range where more will meaningfully help.

> Leaving 100GB of 1TB drive is like buying a sneakers but not wearing them because they would wear.

50GB is like $4 of space the last time most people bought an SSD. Babying the drive with $4 is very far from refusing to use it at all. The same for 100GB on a 4TB drive.