I am building my first non-trivial Next.js app now. It definitely took a couple days to get a simple "fetch data from a third party and render" use case working. And even now I'm not sure if I'm holding it right.
I had a Next.js project due for an interview and it basically took my entire weekend, even with a working prototype in another framework. The interviewer later on told me that the assignment was his way of experimenting to find out if the company should switch stacks. I told him it was the worst experience I've ever had coding.
I was on Google's Web DevRel team for 6 years. Owned all the Chrome DevTools and Lighthouse docs for 4 years and led content strategy for https://web.dev and https://developer.chrome.com for 2 years. Lots of experience building small applications in vanilla HTML/CSS/JS and I build toy apps in whatever frameworks are currently popular. I'm a technical writer by trade so I usually don't have time / motivation / business rationale to dive into a particular framework to the point of mastery but definitely am not a novice either!
This comment [1] describes exactly how I shot myself in the foot w/ hooks. In my head this is how React talks to me now: "Tell me your dependencies. NO NOT THAT KIND OF DEPENDECY!!"