So, you have never used TM. You will discover that you can treat it as an archival tool as well as a traditional backup. Try it. You might like it.
I’m with @gastropod , particularly if there is only one copy of the archived file on a Time Machine disk. One copy is not a backup, and, even if the files are stored on multiple TM external drives, I agree with him that TM is not really designed for long-term archival purposes - more than once I have had Time Machine disks reported as problematic, forcing a new backup from scratch, when I plug the drive back into a Mac. For me, Time Machine is useful if I accidentally delete or save a file I didn’t mean to save, or as a secondary method of restoring a system (I would use a Carbon Copy Cloner disk as a primary restoration method - it’s always been faster for me.)
I use Carbon Copy to copy existing drives to a newer, bigger, faster drive then pull the old drive and put it in an enclosure with USB3. I put in the new bootable drive with all my favorite stuff and more GB’s of space. I turn on the MacBook Pro and it boots up the new drive. Very handy.
Meanwhile, I can plug in and boot up from the old drive(s) should I want any of my older productions or images. Of course this is not possible on my newer iMac, but it has a pretty display for looking at videos and pictures.