The single reason why I prefer Dropbox over the other file storage / sync products is that their sync client works so much better on Mac. It eats fewer resources, is quicker to start and sync once started, doesn't need to 'restart its sync engine', and has the most flexible selective sync. The addition of 'smart sync' to personal accounts is a nice recent addition.
I don't care for all this new functionality targeted at collaboration / corporate use, and I hope Dropbox will start offering a barebones 'I only need to sync files between devices' plan. I've been happily paying $120/y for that for years and hope they let me continue to do just that, or at least stay out of my way they way they have in the past.
I think you should explore some of the alternatives every once in a while, or just maintain a free plan and like 1 folder. Just checked activity monitor and onedrive only uses ~60mb of more ram on idle at least, although (and I believe it's since been pached) it had a memory leak bug at one point and would start eagerly consuming my 16gb of ram if left unchecked. The fix for that was just restarting one drive after startup, no big deal. Even on big syncs (I did ~250gb one time) it syncs about as fast as my upload speeds go and didn't seem to bog down my computer at all.
I don't care for all this new functionality targeted at collaboration / corporate use, and I hope Dropbox will start offering a barebones 'I only need to sync files between devices' plan. I've been happily paying $120/y for that for years and hope they let me continue to do just that, or at least stay out of my way they way they have in the past.