I know this is a 4 year old thread but I was on the forum looking for any threads about Monzo potentially offering mortgages in the future, saw your thread, and thought I’d reply anyway, just in case anyone else comes across it like I did (I imagine your situation resolved itself long ago).
As the high street banks (HSB) are so territorial when it comes to who they will offer services to (i.e. they’re much more likely to offer a mortgage, or at least a better deal on one, to their own customers), in an age of near instant bank transfers it makes sense, to me at least, to maintain an account with one of the HSB’s. And (I know this is a bit of a pain), even get your wages paid into the high street bank and then instantly sent to Monzo. That way the HSB sees your salary and you’ll get the benefits from that but you can still use Monzo as your main bank. I know it’s not a perfect solution, and is possibly slightly annoying, but I decided to go with this setup rather than using the Switching service to try and get the benefits of both old and new style banks. Plus it means I have a 2nd current account that only has money it in for 1 day a month, at the most, so I can use it to “air-gap” my main Monzo account when I want to transfer money to ppl but don’t want to give out my main sort code and account number to them (possibly slightly paranoid of me but it makes me feel better lol).