I strongly disagree with this. As with all engineering tasks, it comes down to what you’re trying to solve.
If a framework can do some significant lift for you, then it’s a question of whether learning it is worth the time and effort saved in writing a bespoke solution that does what the framework offers. You also have to measure how “locked in” to the framework you’ll become and whether or not that will be a problem for you.
One example of a framework I wish I never touched is React Native. The way React Native handles everything from dependency management to coding practices to how to handle breaking changes is nightmarish. More than once on a React Native project did the entire project explode for reasons such as wildly major refactors (with only 6 to 12 months given for folks to switch over), “clever” code having wacky ambiguities and conseqent side effects, a convoluted toolchain breaking somewhere in the middle, and even the package manager itself being conceptually problematic (which I understand is not the fault of React Native but still) I am convinced the team lost more time in learning and coping with the idiosyncracies of the framework than if the project had just been written in Java and Obj C with some useful libraries.
One example of a framework (or game engine or whatever you’d want to call it) I adore is Monogame. Monogame is super straight forward. You’re given a game loop, I/O handling, and some additional niceties. Nothing is obfuscated from you. The tools you use, with the single exception of the MGCB, are whatever you want to use. There’s no magic. Everything is right there in plain ol’ C# for you to see and understand clearly.
As you rightly point out, some tasks are both critical and complex (e.g., cryptography) and shouldn’t be performed on one’s own. Choosing a framework or a library that will handle that for you is prudent. However, most of the features of a framework are not that. Most features are about solving boilerplate and general issues for you so you can get to the task of writing whatever it is you’re trying to write. That’s all well and good. However, choosing a framework can come with as many headaches as they relieve, if you’re not diligant.
The worst part of getting old is listening to younger folk tell you how the world couldn’t have possibly worked the way it actually did work in the past.