I like the calendar, it deals well with all other providers. I like Pass, especially for sharing credentials in the family. Drive is nice, although I switched to Immich. I use the VPN a lot too.
I've recently stared using Pass for some things, and does work fairly well so will likely move non-essential logins there. For VPN I just use Wireshark home.
Just struck me that the competitors also had most of the kitchen sink. I guess Office365 and Google's offering forces others to bundle a similar package.
If you look for it I think you’ll find that they indeed see it as their mission to offer an ecosystem to rival MS and Google. You can do docs and since a couple of weeks also spreadsheet. It’s all decent but very minimal. Drive is aspiring to become a Google Photos/iCloud alternative. It works well enough, including auto syncing from iOS and Android.
I'm a Proton subscriber. I just wanted mail. I don't use the 5-10-15? other products that come with the subscription.