If there has been a significant time between the rejection and now, AND you can improve the editing based on experience since then (and PS/LR improvements), then sure... why not?

I did that about a year ago.  I went through rejections from more than a year prior. Re-edited and resubmitted.  About half were accepted this time around.

One warning -- I would NOT do that with Adobe, since they might very well bring back their free year of LR/PS.  If so, and using same rules as 2018, you need more than 50% acceptance rate, and I wouldn't want to drive down my acceptance this way (unless I had a few that i was sure are now edited such to avoid the prior rejection reason).

It depends on the rejection reason and the agency...

Look at what you've been selling in the last couple of years as a guide for what subject matter might be useful for you to resubmit.

The only point in uploading rejects would be if you believe there's real sales potential that's been missed. With two years sales to look at you have some data that can help.

The other thing would be if all agencies rejected an image, don't bother resubmitting. It's less and less likely to be a random reviewer error the more and more rejections you have received for that image

I originally missed the all agencies part of your reply. By all means, yes, if the rejections are from a number of different places, that's a message that, most likely, the photos aren't worth the time, to re-edit or re-upload.

And also, yes, if the subjects are something that's selling, then there's earnings potential. Otherwise just more padding that's doing nothing in the collection.