Well you can’t expect a 1:1 anime adaptation. That is kind of silly. Anime can add a lot of elements that can be very tough to digest.
You are always going to have to make sacrifices in an anime adaptation. But look at 86, MT & Demon Slayer. When an adaptation is done right it is something that is beautiful and elegant to watch.
Also the only time people bring up the source material is source readers that want to nitpick every little thing. Unless an anime is ass those who are only watching the anime very rarely ask for a comparison to the source.
As good as you say 86 anime is as new novels come out I won’t stop reading them. It may be a good adaptation but it’s not so good I feel like abandoning the light novels.
Also since anime comes after the light novel in most cases it has the benefit of being able to take the best aspects of the original work and magnify them while dropping or lessening what didn’t work. This is typically rare.
Reading in addition to watching anime gets you access to stuff that doesn’t have an anime. Tearmoon Empire for example. Maybe one day that does get an anime but nothing has been announced. One of the funniest comedies out there and it being stuck in book form doesn’t diminish that. In fact the narrator and the way they constantly interject their criticism of the main character Mia is part of the humor that will probably be somewhat lost in an anime adaptation.
Having been on both sides of the pro and anti read clubs I can say I was wrong about refusing to read anything. Looking back on it I can also admit it was a weird preference to have. Then again back then I didn’t read any books at all. The superior experience is read first watch after not anime only or book only.