I think the whole noise issue with mechanical keyboards is way overblown. I have two mech keyboards (with Cherry MX Brown and Black switches), and nobody at the office or at home has ever complained. The Apple butterfly keyboards that some of my coworkers use are subjectively just as loud as mine, if not louder (depending on typing style/force obviously – one of my colleagues seems to really hate his Macbook :) ). Furthermore, rubber dome keyboards actually require you to bottom out on every keystroke, while with mechanical keyboards, there is at least the possibility to avoid that.

I started the mechanical revolution in our ~30p open plan office, now a dozen or so of us use them. I'm using MX Clears, others are using Browns, there's even a red in there, the noise isn't really an issue, just don't hammer the life out if it.

Also higher quality boards with nice heavy plates lower the pitch of the sound so it's less intrusive (in my experience).

Put spacers on your keys. They're cheap, and in addition to muting most of the bottom-out thud, they eat up a lot of the force and spare your knuckles, too.

To install them, find the cheapest kind of ballpoint and pull out the tip and ink tube. The body tube is just the right size to press the spacers onto the key stems. It's miles easier than anything else I've ever tried.

Before spacers, the helpdesk complained about my keyboard noise. The helpdesk! After, no one did.

You’ve got a couple replies saying “not a problem at my office [where I happen to enjoy the use of such a keyboard]” already, so I’ll back you up here:

I have neighbors with mechanicals that bother me so bad I’ve had to pack up and go home for the day. This is over music on noise canceling headphones.

Different people actually have different amounts of trouble with this, with some having lots of problems. Just lucky I guess?

You can add soft rubber rings to dampen that sound almost completely: https://www.wasdkeyboards.com/cherry-mx-rubber-o-ring-switch...

Half our open plan office with 15-ish people in it uses browns, never been an issue. There's almost never complete silence anyway (people talking quietly etc.), the keyboards are subjectively below the threshold of registering as noisy.