You can host it yourself - I don't. The interface is much cleaner and easier to use IMHO, especially if you use password sharing. At the end of the day its a password manager, and there are plenty to choose from. I used to be a big Lastpass fan - but their quality has continued to degrade and competitors have stepped up their game. If I didn't end up using Bitwarden, I probably would have ended up with 1Password.
Yea but you don't have to. I don't have a lot of experience with 1pass/last pass but I assume they're the same. I liked that Bitwarden was free, that I could do my own server, and that I can do dual account sharing via org setup - all free accounts.