This requires a level of expertise that is not available at most small businesses. Going around to each machine with a flash drive is not practical either, especially since this is not a one time thing (because machines die and are replaced).
I thought Windows Server (or maybe just Pro?) makes this easy enough: AD must provide DNS and a CA, and any DC should be able to provide startup scripts to every workstation to install the certificates, set hostnames, etc.
For a more diverse office, with a mix of Macs and Windows machines, maybe there is a niche of an app server box / vm, or even router software that also handles that.
There's plenty that aren't expensive. And they don't need to roll their own software.
Or browser makers can invent a solution for this scenario. That's what software companies do — identify problems that need solving, then solve them. Strive constantly to make things easier.