As a tank, why take the Resolve tree when I can have Triumph?

After the last couple of games where I played a tank, I can't deny that the Resolve tree doesn't feel very impactful as a whole. While the keystones from the other trees tend to really define you play-style in almost every single game, the resolve keystones aren't that much of a focal point. Guardian I like a lot, but it's 90% made for Wardens, so tanks that don't initate but stay close to their teammates. For the tanks that are all about initiation, Aftershock doesn't feel that impactful, both the damage and bonus resistances seem to be mostly hidden numbers. Grasp is sort of a middle ground, sometimes you know it's working good, sometimes you barely know you have a keystone.

As for the other runes: The three major runes aren't terrible, it's just that they're not particularly suited for tanks. Boneplating is good, but it feels more suited to Divers or even assassins than tanks, since it works for only three attacks (thus meaning, get in-get out quickly); font of life again is more a support/warden things; Demoilsh feels great when it works, but it's for Juggernauts, not really for tanks.

The three medium are maybe the worst. Conditioning at best improves your resistances by 20, although it's generally around 10-15 (what am I supposed to feel?); second wind doesn't really heal for a lot, espcially if you a tank with no in-built sustain (Leona, Sion, Ornn) who might not even build Spirit Visage; Chrysalis isn't for tanks, end of story.

The three minor again just don't feel impactful for tanks. Overgrowth is interesting, but you're generally getting 150-200 bonus health per game (300 if you're into late game and fed); Revitalise can have a place, if you have a dedicated healer in the team and maybe other champions that can also heal - still, it just doesn't improve upon tanks' kits; Unflinching... well... Maybe for junglers, since they'll often have a summoner on CD, otherwise you don't want to waste your summoner spells just for a 10% bonus to tenacity and slow reistance.

That said, the precision tree has one rune that heals you for 12% of your missing health per takedown, which is a lot for tanks. And another that shields you for 10% of your max health if you get over-healed (and benefits 300% from allies healing). Plus a miniquest rune that gives you up to 25% tenacity and isn't tied to summoner spells.

Now if I combine both trees, then I start to feel pretty resilient, but it's mainly because I take whatever Resolve runes work best with the "Triumph" rune; I'm not choosing which runes work best on the tank I'm about to play.