I also often buy books! Especially if I really like the book or the author. I don’t think this is an unpopular opinion.

I don’t think that borrowing from the library supports the author in some way you don’t know about — it shows interest in the book and leads to copies being purchased but buying the book directly definitely seems like it would have a bigger impact. But borrowing from the library does support the library! And libraries can be really great for their communities :)