But again, I am not talking about myself, im talking about the hyptothetical person who might not be the perfect customer. My in-laws have had their gas cut more than once because of non-payments, or were only allowed to keep the gas running because they told them "we will wire you the last 3 unpaid invoices at once on day x".

For me to personally end up in this situation the bank would need to somehow SEPA out like 2 years worth of mortgages at once in a short timeframe, which is not a realistic scenario.