I find this an odd comment. No one is talking about 20 backups.
It is poor practice to store anything you care about on a single drive. Drive failures DO happen. Without backups, everything is lost or at a minimum it is a PITA to get everything back.
Having a local backup of some form is the bare minimum anyone should be comfortable with. If for no other reason than you can get working again if a system update breaks something.
Offsite backups are an extra layer of insurance. They can be cloud based or just a clone of your drive that you keep offsite (work, safety deposit box at a bank, etc.).
I recently had a total failure of a 2019 MBP. Apple was able to fix it, but the hard drive was corrupted. Since I had a recent clone of the drive it was easy to restore from that backup once the machine was fixed. Possible I could have recovered my files on the fixed machine, but the backup made the process painless.
I *don’t* care about “old emails to Comcast or OS8”. I do care about restoring a borked system back to a recent usable state in a short amount of time. I also *really* care about my photo library. Insurance will replace all my gear if it gets destroyed in a house fire for example. No amount of money will restore my photos if I don’t have them backed up offsite. My photos matter enough to me that offsite backup in some form is mandatory.
You may not feel the same way, which is obviously fine.