As someone in software for a while that has been the most surprising thing that Open Source did: It massively increased complexity even for small projects because "that's how Google/Amazon/etc do it".

Yes Amazon does Microservice architectures. They also have a few people for every service that knows the ins and outs. You have a team of 5 that now not only has to understand the problem but juggle dependency chains from here around the moon and back so your React App that should have been plain HTML doesn't fail while showing a basically static page.

You won't grow to Google/Amazon scale. It's fine. Just build a simple solution you can maintain.

Working on React/K8s or whatever is mostly you training yourself on your own dime and time to be a potential hire for some Big tech company that will fire you to juice the numbers at he end of the next quarter.