You answered it yourself:
> the owner is responsible for the quality of a project
If you didn’t write, review, or understand the code, then you cannot be responsible for its quality. If you don’t have the skills to write it by hand and understand it, you don’t have to skills to properly address bug reports or understand and prevent malicious submissions.
All of those are legitimate concerns and considerations when deciding if you want to invest your time in a project.
Honestly, if the author had responded “I vibe coded it and didn’t review any of it, but it’s been working for me for <however long>”, that would’ve been fine. It would have been a clear, honest answer that would let everyone decide how they want to proceed.