It actually is kind of about performance. For me it's mostly about de-tooling your project. For example - I have a fairly complex app, at least for a side pro

It actually is kind of about performance. For me it's mostly about de-tooling your project. For example - I have a fairly complex app, at least for a side project, but so far I managed to keep everything without a single external dependecy nor any build tool. Now I have to convert it all to react and I'm not very happy about that, I will have to add a ton of tooling, and what's most important for me, I won't be able to make any changes without deploying the tooling beforehand.