Much cheaper?

  Hetzner
  CX22  vCPU 2 4GB 40GB 20TB Traffic € 3.79 
 
  Hostup
  VPSXS vCPU 2 4GB 50GB  2TB Traffic € 3.54

Hostup also doesn't include the 25% taxes in that price.

Hetzner price doesn't include VAT.

But the real issue is that the price is a bit of red herring: the CX22 plan is not available everywhere (only in the old datacenters in Europe I think) and if you need to scale up your machine you can't use the bigger Intel plans (CX32, CX42 etc) because they have been unavailable for long time, and you have either to move to Amd based plans (CPX31 etc), which cost almost double for the same amount of ram, or to Arm64 based plans.

It seems Hostup has only EPYC vCPUs, no Intel, the 16 core machine seems the same, Hostup has the benefit of offering a 32 vCPU machine while Hetzner tops out at 16.

That is impressively cheap alright. How is the reliability as I haven't heard of them?

As another commenter pointed out, the pricing is very similar. They charge more for networking though and they're not as well-connected as Hetzner:

Hetzner: https://bgp.he.net/AS24940

Hostup: https://bgp.he.net/AS214640

Hetzner also has extra features like firewalls and whatnot that it doesn't seem Hostup has.

Netcup ftw