I guess it depends on how you define “learn Linux”. I “distro hop” repeatedly every day since we use a mix of ubuntu and rhel “at work” and I use a mix of debian and fedora “at home”. Except for that one vendor’s server that runs (REDACTED).
And the vast majority is the same regardless of distro. Sure I might never be able to remember the package manager flags for each distro and need to figure out where config files are stored but all of that is a quick google away. Because I “learn(ed) Linux” in terms of how to read an error message and search for the appropriate terms. Similarly, some number of months back I ran into an issue with a game but was knowledgeable enough to realize it was a Wayland compatibility issue and did a mess of generating config files in x11 so that I could play the game “normally” after that.
But I guess I take issue with your depiction of this. Mostly? You found shortcomings in distros and picked what you like. Good. But you are more describing “learn openSUSE” or “learn Fedora” as opposed to “learn Linux”.