The lack of user management was what killed it for me. I was ready to sell it for management when our Zapier bill was growing to equivalent salary of a FTE support person, but it wouldn't work if there was at least no basic separation for accounts.
Check out windmill.dev they have auth including sso in their open source version. Used it to replace zapier for a lot of stuff and quite happy
Totally understandable. We have however basic user management in n8n for quite a while already and it is available for free. Since the beginning of the year we also have built collaboration, that is however a paid feature.