Those are valid points but mostly when related to small all-in-one type home networks which admittedly is what most people here have.
I think you meant safe against DHCP server failures, not router. My router (and everybody’s for that matter) has absolutely zero to do with dhcp. If my dhcp server fails… then that is my only worry as that is all it does. My router will keep routing away happily. For the all-in-one units, technically your dhcpd implementation could crash without routing, gateway and other services failing as its just a small linux box anyways.
I also don’t find home “router” dhcp implementations to be overly robust or easy to work with (for anything better than VERY simple flat networks). I suspect the vast majority of them would force you to (or do it without asking) clean out the reservation table if you changed a subnet. You would also have to re-key all of these pairs if you changed different hardware as you aren’t going to be able to export/import them.
Change a nic or docker container or restore a vm; you could be looking at new mac addresses. I actually have automated backup validation software that would fail if you didn’t have static IP’s for servers at work.
All in all, I think they have their place but the industry best practice for servers definitely still is static. I read and implement a fair amount of solutions as an SE and documentation still expects static IP for most situations. That’s all I was saying. My intent wasn’t to say you were wrong, just that neither is BETTER… even static.
Besides… he’s now learning about linux!!! Nothing is better than linux!!! oops, next opinion topic