I understand, and my uptime was just to show how reliable Hetzner has been. By “talk me into it” I meant please point out a real kernel security flaw that be exploited without already having access to the system. There very well might be some! I’m not well up on all of this.

Yes, I check my logs and see the constant stream of breakin attempts. Basic security precautions seem to keep them out.

As someone who does full patches every couple of weeks on my servers and reboots every several months, I agree, however there's stuff that can live patch the kernel these days like kernelcare and livepatch by Canonical and more.

Another reason though to reboot every so often is for the server to do filesystem checks on the root partition(s).