Mavis Beacon thought me to touch type on my Amiga as a kid, and I'm grateful to her. In recent years I've been using a Logitech membrane keyboard. It's great for a membrane but mostly it's quiet. I work at night and that's a hard requirement. I'm looking for a mechanical as quiet as the Logitech and it's a struggle. Feels like there is a gap in the market for (really) quiet mechanicals.

There are definitely quiet mechanical switches out there. I'm pretty happy with my Kailh LP Whale silent tactiles. My old IBM style was so loud at night.

Consider Topre, e.g. a Realforce R4 keyboard.