This was actually pretty close to my path as well, I started my career focusing on the popular frameworks, and then later drilled down into the fundamentals. I’d add a third concession to your point: if using frameworks enable you to stay excited about what you’re working on when building from the basics would not, then definitely work with a framework. I try to always lean into things that excite me, right now that happens to be a focus in the fundamentals ☺