Tbh the more I think about what I personally want in a library the more it resembles the Diogenes Club, but keeping in mind it has to be usable and accessible to the public here are some ways to fix it.

>No computers
This immediately gets rid of groups of faggot highschoolers talking, perverts, boomers, hipsters, and anyone else generally unlikeable. If you're in the library you should be there to read books.
>a wide selection of high quality curated books, especially serious works of scholarship. No booktok or propagandaslop. Keep children's literature to its own level.
This is all I see in libraries these days. My university library has 1000x better books than my state library, despite the latter no doubt having better funding.
>comfortable recliner chairs in closed off spaces
As said earlier in the thread the open floor plans just lead to distraction, and the cheap chairs feel awful to sit in for long periods of time.
>no fucking bright lights or sunlight
The library looks like pic related at all times
>strict rules of decorum
Any loudness, messiness, sleeping, unhygienic behaviour, etc. and you're kicked out. Do it twice and you're barred for life.
>Industrial level printer
You just say the name of the book and they print it out for you. Fuck copyright.
>cafe
High quality, cheap, cozy. In it's own little area where discussion is allowed.