I have not used the macOS Time Machine backup system for several years. It just used too much space. Time Machine has a feature that deletes older backup material when the backup drive is getting full. That feature did not work well, at least for me, which resulted in my drive getting full and not working. Over the last few years Apple has improved Time Machine, especially the delete feature. Because of the improvements to Time Machine, I decided to give it a try as one of my backup methods.
The Big Sur version of Time Machine is capable of backing up to AFPS formatted hard drives. Until Big Sur came along, it had to backup to HFS+ formatted drives. I have a 2 TB external SSD drive that I am using for my backup. I only have about 160 GB to backup from my main iMac, so the 2 TB should be good for quite a while, I hope.
You setup the Time Machine backup in the System Preferences area.
Once in the preference area, you need to select the backup drive.
I leave my Time Machine set to “Back Up Automatically”. I am assured of getting hourly backups that way.
One thing you should do when setting up Time Machine is exclude things that do not belong in the backup. You do that by clicking the “Options” button in the lower right corner of the window.
You should exclude other hard drives connected to your Mac and any other items you do not wish to backup. You can leave those items in your backup, but most people just use Time Machine to backup their main system drive. Once you are finished, be sure to click “Save”.
Once all this is set up, Time Machine goes through a time of “Preparing Backup”. Your first backup can take quite a while, so it is best to just set it and forget it.
As far as I can tell, my Time Machine backup works perfectly. The thing about Time Machine is that it is really easy to restore files from your backups.