Earlier quoted context omitted.
There's also a fairly new subreddit, /r/ErgoMechKeyboards/, which only has ergonomic keyboards (simply split ones, or more usually with staggered columns rather than rows, and often a 3D shape). Fewer fancy, expensive keycap sets, and more works-in-progress with wires sticking out. https://www.reddit.com/r/ErgoMechKeyboards/
Can any of these be bought? I love mechanical keyboards, but I can only use an ergonomical keyboard
https://falba.tech/ and https://keycapsss.com/ are two suppliers in Europe, both sell kits and the first sells premade keyboards.
There are small companies selling prebuilt keyboards and kits elsewhere, but I don't know them offhand, except for https://www.aliexpress.com/item/33006060286.html from China (as I have one). There's also https://www.reddit.com/r/mechmarket where there are people that will build the keyboard for a fee, or sell keyboards second hand.
Then there's the larger operations like https://ergodox-ez.com/ and https://ultimatehackingkeyboard.com/ only selling built keyboards.
The Reddit wiki is a reasonable reference, and the Xah Lee site it links to: https://www.reddit.com/r/MechanicalKeyboards/wiki/buying_gui...