If I were shooting 4x5 or larger I could easily feel comfortable using nothing but Tri-X and not feel restricted.

But shooting mostly 35mm and 120, as well as having a wide range of photographic interests and approaches, I have to keep a suitable variety of films and developers on hand along with techniques for making effective use of them.

For example, fine art work or landscapes with TMY at EI 1600 in straight Microphen? Heck, no! I wouldn't even bother using this combo in 120. That's strictly one of my two mainstays for handheld available "dark" candid photography in 35mm.

TMX and ID-11 for fine art work in 35mm? Nah. Seems like a waste of time. That's one of my favorite combos for 120 work.

OTOH, there are some combos I use comfortably in both formats. APX 100 or FP4+ and whatever developer.