Granted, getting into that situation was probably "executives making stupid mistakes" -- seems like it usually is -- and granted, they're probably not saying "we have to do these layoffs because I was an idiot last year", and they're probably not taking commensurate pay cuts. But still. It can certainly and obviously be good for the company's health to have fewer people on its payroll.
Well, the evidence is that mass layoffs aren't having the result of being very positive for companies that engage in them.
Given that what you say also feels true, in my experience, an explanation immediately suggests itself:
Big companies rarely if ever manage to mass lay off only unproductive staff, or net-drain internal orgs. Rather, they're almost always implemented as an across-board X% haircut for most departments with little targeting whatsoever. So in the end, they don't solve the problem you're identifying, and that's why the evidence says they end up doing nothing positive for the company.
And I'd also suggest that very few, if at all, employees has zero contribution. It's just that some of those contributions are invisible to you.
It may be unpopular to say this, but of course it does. Just hire more people if you need to and hope that you're making the right decision. Yes, it has a terrible effect on employee morale, but that's a tough thing to quantify so it won't show up on the balance sheet.
It's too soon to know if the impact of layoffs on most of the companies doing them is positive or not. twitter is an anomaly: that was driven by basic stupidity!
When the $BIGCO I worked for was acquired, instructions were to cut 8% headcount across the board. We were explicitly told that they expected that some valuable people would be cut accidentally, but that's unfortunate. No one should be unreplaceable and if they really are, this is a way to find out and change processes so it can't happen again.
All humans are not just FutureRedundantWetwareMeatsacks that the all knowing bean counters can move around on a board. In reality business is about relationship/small detail institutional knowledge silo'd in individuals/humans proactively getting done what needs doing, many details that get poorly caught by tribal documentation systems.
If your people are truly cogs you don't have a business, you have a franchise, and anyone else can do the cookie cutter things your business is doing, and most likely better/cheaper/flashier. But for some reason HK and all these companies doing layoffs either don't understand that, or they WANT to turn their company into a generic franchise where everyone is interchangeable and lose the flexibility/capability/competency that being a business of interconnected humans gives.
It’s tough. Look at Amazon. They cull the bottom 5% every year. It has a negative affect on morale because everyone is continuously on edge and having a bad month or two can be dangerous. Look at a layoff, it craters morale and reduces productivity.
The best bet seems to be to grow slow, hire and retain the best, and fire the low performers only as needed.
After that, look at corporate giants like IBM. They are laying off, yes, but historically they just lurched along, providing a paycheck to everyone.
There were a couple of dubious episodes, though, where a bad manager tried to do something to people they didn't like. Sometimes it worked (aka, negatively affected people) and sometimes the manager got in trouble instead. So it's not like all good. But it was heavily dependent on the managers you ended up under.
Something like each team is maintaining themselves at a proper rate, laying off inside the team as necessary. But even then you will at times have to fire entire teams, but those aren't really a "mass layoff" so much as "we're not doing X anymore".