This has largely been my experience. Obviously, there are people in these roles that can be "dead weight" just like any other job, but overall the net contribution is beneficial.

I feel like the tech industry has spend the last year or so over-correcting and is now burning the furniture to heat the cabin. Slashing headcount is fine if you're also willing to scale back the things that headcount was expected to build/maintain. Now you have teams that are stretched thin just keeping the lights on. It's not an environment that's going to be conducive to innovation.

The only positive I see in all this is that many of these big companies are now much more vulnerable to competition. Unfortunately I feel like the appetite to take on the big guys just isn't there right now - it's definitely a muscle that's atrophied in the startup space over the last decade.