I guess it depends what you consider "worth it"?  For me Dremastime isn't an agency that generates lots of revenue, but still enough to be worth it to me compared to what little effort and time it takes to submit content.

In terms of revenue you just need to take a look at the poll results. Adobe, Shutterstock and iStock are always in the lead, followed by Alamy, so that might be one you went to try out. After that comes Dreamstime and then the rest of the agencies generate less income than Dreamstime for most contributors. I'd say if you think Dreamstime is not worth your time, none of the other agencies expect for maybe Alamy will be.

In my experience, individual agency recommendations are problematic. My personal agency ranking, for example, does not match the survey result on the right at all - without me really being able to explain it.

iStock doesn't work for me at all, on the other hand Dreamstime and Depositphotos together bring in several hundred Euros a year without a lot extra work. So they are worth it in my case.
At 123rf (which went well in the beginning), with constantly decreasing revenues, at some point it was no longer worth it to me to upload here and I deleted my account.

In my opinion, you won't get around uploading your complete portfolio to the appropriate agency to see then if it works in your individual case or not.