I’m happy with my Proton Unlimited plan. I only use ProtonMail and SimpleLogin regularly, but even for just those two things alone it’s hard to beat $8/month, and I like having the option to connect to ProtonVPN when I need to.
I am not a fan of Proton Drive, I’ve seen people use it for occasionally sharing large files, but it is not a serious personal file storage platform yet. We’ll see if it gets better when they actually release an app outside of Android, but even when actual desktop clients launch I suspect it will be a while before they are up to par with the desktop clients of major cloud services or even self-hosted options like Nextcloud or Synology.
I don’t know what your file storage needs are, if they are very minimal (i.e. you’re fine with uploading files through your browser manually and you don’t need any device syncing) then Unlimited will be good for you. If not, you maybe should consider buying ProtonVPN standalone and purchasing cloud storage elsewhere until Proton Drive matures.