I used a Microsoft Sculpt Ergonomic keyboard (https://www.microsoft.com/en-us/d/microsoft-sculpt-ergonomic...) for many years and LOVED it. I comfortably type at 120+ WPM with no pains or aches. I've owned several. Sadly they are discontinued now that Microsoft exited the accessories business.
Matias, a small Canadian company, has a direct replacement for the Sculpt, but it's not quite out yet (almost): https://matias.ca/sculpted/wireless/
I've also tried various other ergo keyboards, including split and mechanical ones, but nothing was as comfortable over the years as the Sculpt. I miss it every day :( Might just have to give the Matias one a try soon.