i have a Unicomp ps2 keyboard that I've been using for about 25 years that seems to be nearing the end of its service life. it gave me a scare a few years back so i bought a cherry mx board as a backup but the thing gave me doublestrikes all the time so that's not a long-term solution for my next iteration. considering going for another unicomp since i like the chonkyness of it. i always think about a keyboard i encountered back in the 90s that had a special MACRO section onboard, and the old SIIG ALPS keyswitch keyboards. anyone used one of those new-fangled optical keyswitch boards?
modelfkeyboards.com is a thing, too. (I'm not a customer, nor associated with them.)
I'm all in on MX-style keyswitches, because you can make keywell keyboards such as the Dactyl Manuform with them. See for example [email protected]. Keywell keyboard design and manufacturing is... shall we say, much more decentralized than Model M keyboard design and manufacturing? :) Many people can make you a curvy keyboard, and there are many varieties, or you can make one yourself, and customize its form as you wish. But this is all far afield from what you actually want, I'm afraid.
Your question also brings to mind beamspring switches such as https://kono.store/blogs/keyboards/silo-beam. Similarly that does not appear to lead to the same kind of experience of clicking a button, paying your money, and getting a pre-existing keyboard removed from a warehouse shelf and shipped to you in a few days, as you would get with Unicomp.
I think my taste in keyboards is possibly slightly more vanilla than those cyberpunk rigs i see in ergomechkeyboards ;D I would love to get a chance to try out these oneoff alt boards but I get the impression that custom built ones run into the absurd dollars range.
Mass-produced ergonomic keyboards arearound $400 USD thesedays. The more of it you build yourself, the cheaper. I can build one for some $15, having already sunk the costs of a 3D printer, soldering station, some switches, some keycaps, a few Pro Micro boards, and lots of time learning about it.
But before my wrists started hurting, I never went for expensive nor weird keyboards. An IBM Model M passed into my life a long time ago, and quietly back out of it after only a few years, relatively unappreciated... Crazy, I know!