1Password is a better deal for their Teams package compared to Bitwarden last I checked. You get 10 teams users for $20, while Bitwarden is $4 per. Enterprise tier Bitwarden is a bit cheaper though.
You cannot control anything that happens inside their apps and when you add a password that is then send to their servers 'encrypted' and is then 'decrypted' on another device that means that the key to en-/decrypt the password moved along with it.
So in the end they have the password to your passwords and that's an issue for me. I don't want that and I wouldn't want anybody else to be in that situation because besides abuse there's also always the option of data leakage and then you're really screwed.
The master password you use to unlock the manager is used to encrypt the passwords themselves along with other metadata.
It is the strength of the master password that guards the passwords within.
Indeed, you are trusting their software to be correct and safe like you would any other software and vendor.
IF that's really the case then the whole thing is pointless and you can just revert to a KeePass file on a web share or something similar.
Also decrypting the passwords in the web interface is either done in Javascript which would open the master password to all kinds of attacks or it's done server side which means they have the password.