I’ve been using Slackware since 1994, saw redhat and Debian being born.

Slackware has been around long before those distros appeared

Yes, that’s true and a bad or undersized power supply also but in my experience it is much more likely to have a bad disk than to have something else fail

I would check the kernel messages (sudo dmesg) and check for errors on the ata bus. If there are it’s most likely the disk that is failling