Summary: Shop for dedicated router with 2.5 GBit support.
I like my EdgeRouter ER-4, but its a couple years old now and doesn't support beyond Gigabit. It does max out my Gigabit network. Faster than Gigabit seems to be teased with newer Cable Modems with 2.5 Gbit support.
I hear good things about various Mikrotik routers and 2.5 Gbit SFP adapters being put to work. Some have it working with 5Gbit SFP modules too.
Both have their own OS. I think both focus on wired lines. Though Mikrotik may have a model with Wifi support. I prefer to run WiFi AP separately so its easier to upgrade or setup Mesh systems. I use my old Router as dedicated WIFI AC Access Point, running DDWRT firmware with all the routing functions disabled.