How to up the chances of drops for Mounts

I’m still missing 9 mounts (the horses only, not the armor or trophies, I haven’t even counted that yet). They Are
Brigand’s Steed (World drop)
Cavalier’s Steed (World drop)
Decaying Steed (Treasure goblin drop)
Grisly Calico (Unknown)
Plains Yearling (Unknown)
Executioner’s Steed (World drop)
Seal Brown Steed (World drop)
Taiga Roan (Fractured Peaks)
Trapper’s Steed (world Drop)

Some of them are considered “common”. I have more than 1500 hours in this game… what does this game want from me? I do legions, helltides, dungeons, open world, events, world boss… Am I missing something? How do I get these realistically??

I feel like most of those mounts are going to be showing up in the shop at some point.

I’m pretty sure I’d read that many were data mined but not yet found.

It’s really just RNG. I got the decaying steed when game launched and just got the barding of mount Arreat last week, both from goblins which Im sure I’ve killed hundreds of by now.

The only horse cosmetics I’m missing is the wandering death barding and the chipped claw or w/e from Ashava.

It wants you to stop playing

I’m still missing the mount armor for avarice and ashava