This sounds like the problem I had, which I'm trying to solve with https://nachapp.com - instead of my attention being split between several apps which focus on specific TYPES of content (i.e. everything you listed), it focuses on a specific WORKFLOW - acting as a central high-level hub, based on the core concept of achieving personal goals (which I think would be the same thing you mean with "learning process").

It isn't trying to completely replicate the storage of everything you have in the apps you listed. Instead, it's trying to focus your attention to what your real goals in life are, so you hopefully end up with quite a minimalist approach, where you're discarding a lot of info that's essentially a distraction, and really able to focus on only saving the stuff which is relevant to your goals, and keeping a hierarchical list of actionables as your method of recall for the content, instead of it being scattered randomly across a dozen apps.

If this sounds like an attractive solution to you, would be great to talk about this a bit more (you can reach me through the site's contact form), because I want to work out ways to make the app smarter for covering that exact workflow you're talking about (discovery -> actionables).

Note that the app may look pretty "simple" from the landing page, but it is also very much aimed at power-users (I personally have a couple of hundred active steps+goals).