People have been running real businesses before the cloud providers existed. Of course you can run a business with rented dedicated servers.

My business is running on Hetzner. And many others as well.

I have hetzner vms going on 500+ DAYS without restart. I've been a hetzner customer for about 8 years now. Aws has been down x10 times more than hetzner has. And even when hetzner has issues they are localized to a single DC at worst, most often a single host is down. When aws has issue.. The whole internet has issues. Or their central region goes out, also can affect their other regions.

For the small/medium businesses infra I manage here in bulgaria , the same thing would cost 5-10 times as much on aws just for the compute, throw in 1tb of bandwidth.. And this makes no financial sense.

On hetzner I pay 40 euros for 2 vms, dedicated ips, daily backups, 100gb of ssd external storage, and firewall.