"Enterprise class" wifi routers from ten years ago sell on eBay for about 1/5th as much, and work just as well for most home or small business applications.

It's worth being careful here: a lot of the affordable enterprise-class routers from 10+ years ago aren't as fast as cheap consumer hardware - like the OP or just a decent mini PC. The primary arguments for the enterprise-class gear are around feature availability and certain aspects of reliability (redundant power/fans, better heat tolerance, higher quality components). It's also worth remembering that this kind of gear tends to be built for dedicated environments: loud fans, higher power draw/lack of power saving features, etc.

Beside the potential performance and environmental issues the other big downsides tend to include firmware availability - either because download from the site requires a login on the vendor's site or, increasingly commonly, the gear has hit LDOS and images just aren't posted. Obviously there are other "unofficial" places for such images, but the risk/legality are a whole other (potentially serious) question.

There's an additional issue mapping the requirements of home networking to enterprise gear: Ethernet switches are lousy firewalls (little or no NAT, primitive built-in security, DLNA/mDNS and friends aren't really sane options, etc). Finally, even at "1/5" the price the gear may still be quite a bit more expensive than other options. And if it's not expensive, it's usually because nobody wants it any more because of the issues mentioned above (being near- or beyond- LDOS).

FWIW this is from someone who literally built a commercial-class machine room in his house with dedicated AC, subpanels, commercial UPS, etc for data center class Ethernet, Fibre Channel and Infiniband switching as well as carrier-grade routers and still runs "enterprise" grade WLAN and switching and can lay hands on as much as I could reasonably want without too much drama or cost... Going down this road can absolutely be amazing if you either have a.) the background to properly source and run the hardware/software or b.) have a driving desire to learn how to do so or c.) have some very atypical requirements for home networking. Otherwise it tends to not be something to be done lightly.

Aren't they also missing security patches? I'm not sure about you, but I'd rather have SOHO routers with up to date firmware, than enterprise routers with out of date firmware.