Yeah, I don't think you get to that unnaturally big scale without spreading yourself thin. This is largely a matter of macroeconomic incentives (and policies), I'd say. But people think that Google and others do big and important stuff. Which is true, but it's not the whole picture. A large part of such companies (or at least some of them) ends up being a highly-optimized money pumping mechanism. This typically means more and more ad-hoc work, custom development, lower individual impact, highly cost-sensitive stuff. Of course they're going to outsource to India and even then they won't just pick the good Indian devs (which are already much cheaper anyway and may be totally justifiable), since a large part of the revenue structure comes from extracting tiny profits from a lot of labor-intensive stuff.

The focus on SaaS in recent years also doesn't help at all, because it shifts work to the service provider in practice. Whereas previously the customer got to manage the complexity they created and keep the pieces when it broke (with varying levels of stability guarantees over a core product), now the service provider must maintain a lot of debatable ad-hoc stuff for who knows how long and the customer pays a subscription. I've seen a lot of half-baked random crap which was only justified by the fact that one single customer wanted it at some point (double damage if management thinks the feature has resale value, yet obviously it was cost-sensitive enough that it was largely made out of duct tape). Plenty of companies say they have actual products but they largely have a pileup of random features from customers. At any rate, that's not something that can be done without cutting corners. And even that gets progressively more difficult over time as things weigh down heavily.