>>7680349
>is it actually just common for artists to have gaps in their lines?
Yes. It's preferred for things with even just a slightly sketchy style. Poorly connecting lines pretty much always looks worse than just not connecting them at all.
It's also an intentional thing. When you're drawing lines you really need to stop thinking about it as an outline, it's not. It's a form abstraction. Form has depth, form gets lost. There's not always going to be a perfectly enclosed bucket-fillable area to work with.
Ultra clean pixel perfect lineart is kind of a meme, and there aren't many serious artists who actually do it who didn't get beg-trapped into it. It looks really, really bad and artificial unless you have some exceptional representation abilities.