The first example cited in Obsidian is easily solvable. Stick to consistent terminology for notes covering a particular subject and the back links panel will auto suggest linking all the notes that cover that area together whenever you create new ones.

As for rediscovery of old stuff, the best solution is to get comfortable with the fact that certain notes won't resurface and to let them die. This is actually a good thing. It allows you to keep focus on your interests as they evolve. Even the legendary Niklas Luhmann, whose paper zettelkasten was arguably the inspiration for the current lmk craze had what we called "black holes" in his system—there are several notes he filed that never saw the light of day again. This was by design. These systems are supposed to be dynamic mechanisms for helpings you think, not immemorial retrieval mechanisms. If that's what you want you might as well make every note chronological.

Trying to use a PKM strictly as a "remember anything at any time" is largely missing the point. The goal is to create knowledge by stringing relevant ideas together and, as Luhmann did, to use the system to produce surprises. The best way to do this for obsidian in particular is to use terminology and link liberally whenever some term occurs in a note even if it at first seems completely unrelated—that's what you want, you want the system to surprise you as you navigate h the graph of notes.