

Neither do I - I use either my phone, or my smart TV, or my fire stick. SSO works fine there, or you can use the QR based session transfer to SSO on your phone and then “sign in on another device” or whatever by scanning the QR your other device is showing. I think they call it quick connect or something.
It does what you want.
And if you think Grandma can’t figure out scanning a QR code, Grandma is also not gonna figure out MFA lol.

I’ve been selfhosting Synapse on Docker Compose for… maybe 1.5 years now? I’m also running bridges. I’ve never had to do monthly maintenance. I have around 20 users (my friends) active daily, a few federated rooms. I have message retention on and it “just worked” for me (not sure why OP had to do extra config)
I only find two of the critiques to be true in my experience:
Overall synpase for me has been very much “set it and forget it”. I can’t remember when I last did server maintenance.