Not exactly how I’d phrase that, but you’ve stumbled on a serious point. In the UK we have the expectation that banking should be free. Sounds great, but this means that the indebted end up subsidising the debt free - as that’s (crudely) how banks make their money.
Personally, I’d prefer to pay a small amount for a bank account. That would also benefit Monzo as, due to their lower cost base, they’d be able to undercut the competition in a way they can’t (visibly) at the moment - mostly because (as others have outlined) traditional banks’ charges are obfuscated behind fees, charges and APRs.
Ultimately, I’d like to see a different form of banking that isn’t regressive like it is at the moment. But Monzo can’t change the whole UK banking system / market overnight on its own. Maybe I’ve drunk the kool-aid, but I believe that Monzo is a force for good in the industry. But, as they establish themselves and grow, they also need to find a way of being (in the short term) solvent, and ultimately profitable. It’s not the cheapest overdraft, but nor does it seem hidden, seeking to take advantage or profiteering. And as customers, we’ll all make our own minds up about it - and it’s okay for us to reach different conclusions.