Among the 4 production B2B Rails apps I've been adding features to in the past year, the only one using jQuery was created 13 years ago. None of the others ever used jQuery, and using Hotwire Turbo to replicate SPA functionality is easy nowadays.
One of the Rails apps serves a Flutter mobile client on the front-end, and as much as I appreciate all the lifting Flutter does for me, the sheer amount of code required to support that is enormous and laborious in comparison to writing a few Turbo frame tags in the fullstack Rails app. If not for a few gotchas that the client app needed, that mobile app would have been done with Jumpstart Pro iOS & Android with Turbo Native (great code reuse potential).
Users of Rails apps leveraging Turbo frames or streams don't think those apps feel more shiny and cool and performant than legacy SPA frameworks such as React, and the modern Rails developers spend less time churning out code.