Exactly: you may not be able to fully understand the OS you're working with, but you can abstract it away and use it anyway. This isn't "technical debt", it's

Exactly: you may not be able to fully understand the OS you're working with, but you can abstract it away and use it anyway. This isn't "technical debt", it's something you need to actually get your job done: without the OS, you simply would not be able to actually create the thing you're making. Similarly, whatever you're building likely uses a microprocessor somewhere. You probably don't really understand how that works, and would not be able to build one from scratch. But without that CPU, you wouldn't be doing your job at all. The phrase "standing on the shoulders of giants" comes to mind here.