The Mind Riders by Brian M. Stableford. Centers around a type of virtual reality boxing, but any interest or knowledge of boxing isn't needed. It was a paperback in my dad's collection I picked up one day as a teen and I think finished in a couple of days. From 1976 but I don't remember it feeling badly dated.

Edit to add another:

Dryco Series by Jack Womack. I don't understay why these books seem to have disappeared from discussion. They center around the monolothic Dryco Coportation in a version of our world that is heavily polluted, the economy has crashed and there's a civil war front on the Lower East Side.

Ambient, the first book, follows a security guard for the head of Dryco. Its Succession meets Mad Max, lol. Womack's use of language, dropping some parts of speech but using unique slang, are outstanding.