Is there even a benefit to using overleaf in the first place? My understanding is it just hosts a latex compiler and modern looking, though not superiorly functioning ui. Just take the evening it takes to set things up from scratch and work out any kinks if there even are any. I really dislike this over reliance of putting everything into "the cloud"

I suppose it's a convenient way to have a "Google Docs" type environment for your Latex documents. There's a self-hosted version available, but it's not very straight forward to set up and get fully working https://github.com/overleaf/toolkit/.