Revolut and Monzo have way more outages but are small enough to not draw the ire of regulators. You are living in a fantasy land if you think they operate with less risk than a major bank
When did Monzo last have an outage? I get them with Curve and Starling, but they use GPS for their payment processing. Monzo have built their own from the ground up.
I've got a Monzo account, which I'm a big fan of. However, Monzo have definitely had more outages and planned maintenance than the other online banking service I use, which is provided by a different UK bank. I'd consider that a reason not to make the jump.
I've been a user since the beta too, and while they do have less outages than when they used a third party payment platform, they certainly still have more outages than my other UK bank.
Other banks and stuff have outages. Monzo just bothers to tell you about issues.
Also the longest outage I remember was when the third party card processor's server broke and it took them a few days to rebuilt it (which is pretty unnaceptable in this day and age)
Is that after they left beta? I noticed quite a few outages, but that was while they still had the big beta disclaimer on things. I've not had any trouble since.