I liked the first anime series, but (for me) the visual novel was incredibly tedious and boring. Did a refund of it on Steam about after 10-15 mins (from rough memory).
Theres no way I'd be able to put up with it for the whole duration.
Maybe I'll get around to trying one of the others you mentioned in a different comment. :)
And then there are masterpiece VNs absolutely chock full of choices and an extremely complex story graph, like Subarashiki Hibi or Fate Stay/Night.
(And, in my opinion, it's one of the worst things ever written.)
There are many equally valid "true" endings, not counting all the side endings. Sounds like it wasn't your cup of tea, that's fine. No VN is universally loved.
Also bonus link to one of my favorite tracks in the game: https://youtu.be/dQ5g1Va7CjI
Most VNs are structured as routes. There are a handful of independent stories. The reader not choose how the story will unfold, but rather chooses one of several linear stories to follow. I would classify that as a fundamentally linear story. The fact that the route is chosen by a choice in the middle is not really different from choosing the route from a menu at the start.
SubaHibi is even more linear than that, because the playing order of the routes is enforced. There is one "True" ending, which is required to be completed last and is the only one which resolves all the mysteries.
(I say the True ending resolves all the mysteries, but the mysteries were resolved to my satisfaction by the end of It's my Own Invention. That wasn't by design, though.)
Anyway we aren't going to agree here. I am interested in two things: what VNs you do like... and what VNs you would consider non-linear. The discussion can't really continue without a point of comparison.
So yes, it's piracy, but it also isn't a perfect reproduction.
One might think that the fact that choices are flattened into a purely linear story would ruin the experience, but most choices are so vestigial that removing them is an improvement in my book.