However, I remember a case when I was the culprit - spam was being sent from one of my servers (one of the users had a common username and password, something I should have never allowed) and Hetzner notified me immediately, but they didn't block the server in any way (something I'd expect). They gave me some window for explanation/solving the problem. I was very happy with how they handled the issue - but of course others may have had different experiences.
I suppose billing works extremely well for most GCP customers as well.
As for me, I hosted a side project on Hetzner a few years back for some European presence. IIRC I used PayPal for payment and they didn't support PayPal recurring payment, so I had to settle an invoice each month. Used them for about two years without problem, then missed payment for two months during a chaotic period when I didn't notice their monthly invoice emails. I got exactly one email reminder about missed payment titled "Reminder" (yes, that's all, I got all their correspondence in front of me right now) before the final "Cancellation of Contract" email and termination of my account. At that point, politely pleading with them to reinstate the account was useless, I only got a threatening letter back demanding a wire transfer of the ~€60 I owed within three business days or risk being sent to collections.
Was I in the wrong? Sure. Were they friendly or patient? No.