Akira1364
A) The person you're replying to is simply quite wrong about the amount of Pascal libraries available. There is no "domain of interest" I can think of that does not have at least one "defacto" library for it.
More commonly though there's four, five, six or more libraries for any given thing to choose from, which often turn out to each have specific strengths such that you may very well end up using more than one of them in your project.
B) They would almost certainly probably not like Go. Object Pascal as implemented by Free Pascal is a language that effectively embraces with open arms almost all of the things that Go actively avoids: for example, traditional (single) inheritance, operator overloading, both function overloading and generics, and so on and so forth.
As far as inheritance specifically, the general indifferent attitudes towards it of "there are definitely times and places where it makes more sense than anything else to use" amongst Pascal programmers are in my opinion basically a direct result of the fact that "bad experiences the compiler developers personally had with inheritance as specifically implemented by C++" are NOT something that actively factors into their decision making process or something that they really think about or care about at all (or more broadly, something that users of the compiler generally think about or care about at all).
This sets it quite far apart from other languages such as Rust, where "things C and C++ arguably did wrong" are in fact heavily influential and both thought about and discussed regularly.
Also, yes, Free Pascal is entirely self-hosted from the bottom up, making use of inline assembly blocks in some places where it's necessary. It is to Pascal what GCC is to C and C++, basically (which is to say, it has no real dependencies on toolchains other than itself).
https://www.freepascal.org/docs-html/ref/refsu69.html
That said, as far as at least Free Pascal goes, there isn't actually even a specific function called `writeln` with a real body that you can go and look at somewhere.
It's a magic language-level intrinsic that gets broken down into calls to various other intrinsics by the compiler based on what's passed to it.