What? Is this really controversial? Sometimes you need a UI library, sometimes you need really quick interactivity to toggle a menu. I use alpine.js on my marketing pages, and I use vue/svelte within sections of my app.
But anyway, it’s impossible to tell from just the package.json file whether React and jQuery are being used on the same page, or just both used in different parts of the app.
Actually, when I was starting with React, then for a while Talkyard did use both jQuery and React on the same pages (not a good idea, I agree). I was careful to avoid the bugs you have in mind from happening, so that wasn't a problem,
however, loading & using both libs wasn't good for performance — just parsing and executing the 30 kb min.js.gz jQuery bundle took maybe half a second? a second? on mobile phones, back at the time (2.5 years ago).
edit: and it still is today, just a tad updated: https://reactjs.org/docs/integrating-with-other-libraries.ht...
Thanks for the link. I think I saw that page, or sth similar, back then. ... Now I found an old question I posted at StackOverflow about jQuery + React: https://stackoverflow.com/questions/27646347/is-it-okay-to-d...
I use Bliss.js, https://github.com/LeaVerou/bliss for some parts of Talkyard nowadays, where React would be too much. Bliss.js is sth like 3 kb min.js.gz. (But jQuery itself is gone nowadays, it was too large.)
I would seriously consider dropping this dependency. React's performance is fairly acceptable.
I agree that React is fast enough. React is pretty large though, takes a bit time to parse and compile the code, on mobile. And none of its features are needed in this case, and could instead cause conflicts with other libs.
What I'd do, if anything, is a custom build / fork of Bliss that removes most of the code, so 3 kb becomes Bliss maybe just 1 kb "Mini-Bliss".