In the old days, it didn't matter how _good_ you were; basically, your site was going to look more or less like the site created by someone who just started and tried really hard for a few days. You could copy/paste HTML from other people's sites _and just have it_. Now, nothing works because there are tokens and authorization and APIs everywhere.
I don't see anyone complaining that you can't just build a car from scratch in your garage. That would be crazy, right? Yet, somehow, anyone should be able to learn how to code professional internet software with little effort and understanding.
If you want to use React, I don't understand what's so hard about the [introductory documentation](https://reactjs.org/docs/add-react-to-a-website.html)? It's almost pure HTML and has [a lot of help](https://reactjs.org/docs/getting-started.html#try-react) for extending it from there.
This is honestly a lot easier than what we had at the beginning, where even documentation for HTML tags wasn't so easy to find.
Maybe this is still too complicated, but the lower bar is there, whether you like it or not. If I don't know how to use scissors, I'm going to be a shitty barber.
Check this issue: https://github.com/flutter/flutter/issues/11609
Many functional aspects of react can be hard to grok. HOC and currying isn't obvious to everyone.
The surrounding tooling sure is complex af and the little inconsistencies in how everyone does things in the community doesn't help. If the person wants to keep themselves to using a blackbox, they will face problems with react at some point which will force them to learn about how all of this works. React will introduce performance issues that normal js/html/css can easily forget about if you are not careful. Then you will need to learn about lifecycles, debugging tools, and lot of other things simply to make your app not suck.
But you might be too far down the rabbit hole. To use react involves learning a series of things (npm/react/command line). To use Jquery copy 5 lines. It is so easy to get started and so simple to work with.
JQuery is the right choice when you are not managing complexity. When you want a simple powerful abstraction. It's usually the right choice for non-programmers who want to do a few things. It's a good choice for programmers who are not building applications.