Yes. If you're a front-end developer at some capacity, developing anything of use for > 0 users, you'll have hell of a lot of browser compatibility issues.
People will browse your app from ancient mobile phones. Weird smart TVs. play consoles. Chinese browsers you've never heard of but come bundled with some we-something, they will browse your app from PoS, from a DJI smart RC, from a fridge. And from IE6.
And you know what's the best way to mitigate all that mental load? You just start upfront with a framework that was already battle-tested on all these weird browsers.
What framework do you recommend for wide browser support? React certainly doesn't claim to support anything like feature-phones or IE 6; the lowest they go is IE 9, and that's only if you load additional polyfills: https://reactjs.org/docs/react-dom.html#browser-support
People will browse your app from ancient mobile phones. Weird smart TVs. play consoles. Chinese browsers you've never heard of but come bundled with some we-something, they will browse your app from PoS, from a DJI smart RC, from a fridge. And from IE6.
And you know what's the best way to mitigate all that mental load? You just start upfront with a framework that was already battle-tested on all these weird browsers.