Same problem here. Macbook Air M2 with 8GB of RAM, Ventura 13.5.2.
Dropbox uses ~630MB of memory after a clean restart. 448MB of that is for the main Dropbox application, which is bad enough, but then I noticed all the Dropbox Helper processes that are using a bunch more memory... and it's using hundreds of threads?! This is while it's doing NOTHING, and I only have a few folders (maybe 100 files total) selected for syncing.
Over time the memory usage creeps up steadily. This is ridiculous! I've used Dropbox for a long time but I might finally have to switch.