That’s committing the cardinal sin of cherrypicking your backup contents. You may end up forgetting to include things that you didn’t know you needed until restore time and you’re creating a backup that is cumbersome to restore. Always remember: you should really be creating a restore strategy rather than a backup strategy.
As a general rule I always backup the filesystem wholesale, optionally exclude things of which I’m 100% sure that I don’t need it, and keep multiple copies (daylies and monthlies going some time back) so I always have a complete reference of what my system looked like at a particular point in time, and if push comes to shove I can always revert to a previous state by wiping the filesystem and copying one of the backups to it.