Hosting on second- or even third-tier providers allows you to overprovision and have much better redundancy, provided your solution is architected from the ground up in a vendor agnostic way. Hetzner is dirt cheap, and there are countless cheap and reliable providers spread around the globe (Europe in my case) to host a fleet of stateless containers that never fail simultaneously.
Stateful services are much more difficult, but replication and failover is not rocket science. 30 minutes of downtime or 30 seconds of data loss rarely kill businesses. On the contrary, unrealistic RTOs and RPOs are, in my experience, more dangerous, either as increased complexity or as vendor lock-in.
Customers don't expect 100% availability and noone offers such SLAs. But for most businesses, 99.95% is perfecty acceplable, and it is not difficult to have less than 4h/year of downtime.