What prevent Hugo from being supported by GitHub pages? I have never understood the "Jekyll integration" thing, you're just pushing static assets created by your static site generator to GitHub, so why would it be different from a generator to an other?
Github is based on ruby, so is jekyll, so its a frictionless setup that's free.
You can use netlify but there's more setup to that than github imo.
with github you can also have as many sites as you want, little unknown fact just make 100 organizations and you have 100 sites. Content is open to anyone though. But the option is still nice to have
Github runs Jekyll for you, that's all integration there is. Meaning you do not have to push the generated files to update a Jekyll page hosted on there, only the source files.