I run an older half depth supermicro server with a sfp+ PCI card for my router. At this point, it feels like dedicated boxes just aren’t worth it for routers except for enterprise where I need a support contract.

That’s not entirely true. Having a router with multiple interfaces is useful for multiple physical networks like VoIP, OOB, dmz, etc. We use vlans a lot for that now, but it’s not fair to say only two ports is the only choice.