Using existing code is fine, that's how most software is built anyhow. Only masochists build from complete scratch.
EDIT: I've been getting a lot of down votes for this stance, surprisingly. Why not share your position if you don't agree? There must be a bunch of hardcore people on here who are writing directly on the metal in machine code. Short of that, you are in fact using someone else's code in all your projects.
This seems to conflate two entirely different ways of "using existing code". Using tools written by others is technically "using existing code", but that's an entirely different thing than incorporating existing code into your projects.
I think that when most devs hear "using existing code", they're thinking of the latter, not the former.
How is calling a library and using a function someone else wrote not the same thing as using a function someone else wrote in any other way? Cite your sources by all means but still the difference is a semantical one.
What I'm saying is that calling a library/crate/whatever is an entirely different thing from using a tool like a compiler/IDE/etc. In the former, you're incorporating external code into your project. In the latter, you're not.
I think most people wouldn't say that you're "using someone else's code" in your project just by using a tool written by someone else because the tool's code is not being included in your project.
Perhaps I misunderstood you, though. Your statement "There must be a bunch of hardcore people on here who are writing directly on the metal in machine code" heavily implies that you believe that using an assembler or compiler counts as "using existing code". In this context, I don't think it does.
By the way, I do, in fact, sometimes write code directly in machine language. Not large amounts of it, of course, but some.
It's the classic "building on Chrome cedes control of what the web can do to Google". But I think most people aren't interested in rehashing that discussion here - a search for "independent browser engine" should turn up plenty of arguments if you're interested in other positions.
Ladybird is frickin awesome but give it 10 more years and it still won't be an equivalent to 2024 Safari/Firefox/Chrome without a lot more funding than it's already getting (~100-200k/year in sponsorships).
