As long as it’s a web app, it’s usually fine and can provide an extra layer of security. The app does need to have some support for sso if you want it to be seamless though, without logging in twice.

Most of my services are internal only, but sometimes I want to give access to someone on the internet without also giving them VPN access. If the app doesn’t support any kind of login, having an Auth proxy in front of it really helps for that use case.

Remembering lots of passwords isn’t a big deal if you have a password manager, but not having to log in to each app separately is nice. It’s also nice to be able to put Auth in front of things that don’t support it natively.