If I ate a sandwich over my old thinkpad and crumbs got under the keys, I'd just push the keys harder to crush the crumbs into dust. Total non-issue for the better part of a decade.

It's only when keyboards become thin and delicate that durability becomes a problem.

The membrane still has holes in it, letting dust get trapped inside the delicate parts. It just reduces the risk of dust getting inside in the first place

I've tried with compressed air and it's only a temporary fix. Same issue w/ 2016-7 MacBook Pros.

I'm convinced the problem with these keyboards isn't always debris under the keys. I've noticed it's often E and R, the keys right above the heatpipe system, which suggests that heat could be warping or damaging the contacts. This is even worse.

I have owned five Apple laptops and six Apple keyboards in total.

Two of those I used hard enough that keys fell off.

This latest is the only one which has had issues with the keys not working. Even the ones missing keys, there was a small nub left that still worked.

The main key failure has been the left Command key, which is an utter disaster. I’m furious about it.

Not quite furious enough to give up 15 years of the Mac. But close.

Over the past 20 years I have owned various laptops from HP, MSi, Acer, Apple, and also (for my desktops) external keyboards from a number of additional vendors. The only keyboard that ever had any trouble was after I gave it to my 4yo and over time he got all sorts of food inside it.

My work 2018 mpb showed a stuck key after 2 weeks (no food near it), and it obviously is not bad luck on my part.

I returned a 2018 MacBook Air with the membrane because it failed with the same failure mode. Then I got duplicate key presses.

I now use a thinkpad.

Yes, if you used to get a bit of toast stuck under the keys of an old Thinkpad you just bash the key a couple of times and the crumb breaks up a little. Problem solved. Clear out any crumbs, dust and accumulated pet hair every now and then for neatness.

Only '16 and on model Macbooks seem to require a cleanroom for the keyboard.

Maybe, but I've never experienced that problem on any laptop I've owned. I've been buying laptops for almost 20 years.