This is dumb and "obvious" but the advantage of the layers of abstraction is that a lot of people share layers of abstraction. So the issues need to only be found once, so to speak

Of course you lose specialization and you end in "the image decoder supports some weird format which allows RPC " territory but most software can barely handle the high level bugs.

It's pretty crazy how something like Django exists, powers thousands and thousands of websites, but has perhaps less than a thousand contributors overall? Less than one person per project. Now that's an amazing payoff!