Have you ever tested these drives before ? If you tried different brands but all shred I would think it either the drives or how the disks were stored. Cool temps and Moisture over long term make the mag coating very soft, even moldy.
I have never had problems with heat, it gets up to 100f here during summers and it has not ruined any disks yet (it gets into 90+ in this old house) and many are 20+ years old.
My suggestion is to take one of the ruined disks and use a clean finger gently pull from middle to edge in the slot, do that a two times and look at the media, if it is badly rubbed/scratched then the disks are all bad..
Yes, You can scratch the media with dry skin and too much pressure so do it gently.

I once had one drive that was hopelessly always scratching disks no matter how well I clean its heads. I'm guessing the heads must have some diffiency, but I never figured it out. The only disks it didn't scratch were brand new disks.

The drive wasn't like that. It became like that after I fed it mouldy disks. So somehow that must have permanently damaged the heads. I'm guessing this is what happened to your drives as well. It was then that I learned to clean all disks when I first receive them. Once I did that, it became apparent how much dirt/mould is built up on many of those disks.
Unfortunately, the media cannot withstand long periods of basement/attic storage. The humidity and extreme weather are too much. When I get disks that were stored nicely, then they just work without any trouble nor need of cleaning.

yes the disks were stored in a place with high humidity and cycles of cold and heat
yes the drives were stored there too
but...

but what is physically happening to the drive heads to start ripping the disks apart? the heads are made of a smooth white ceramic stuff and they are not dirty
the cotton tips always come immaculately clean
I dont see any rough hedges, cracks on them

the grooves are so deep that its like something is biting into them ... the disk developed a transparent wring around track zero

are the drives irremediably destroyed ? I refuse to admit that you can destroy a drive head just by playing a moldy or old disk through it ..
The last drive I tested started well .. reading the disks, finding bad sectors here and there as expected in a disk recorded over 25 years ago
But then SOMETHING HAPPENED and it started scratching them all like the previous 2 drives... including disks that it had already read nicely

I beg someone with expertise in this old systems to help 🙁