I’ve been there, too.
Personlly, I don’t think the answer is more “ways” to get Dragonite (that one actually got implemented: Dragonite Gnomes, Wandering Merchants, Underspire Diamantina, and now PVP Gold Emblem shop), but instead:
I get it: Dragonite is rare and expensive* by design. But the lack of meaningful player agency in the primary way of obtaining it (perfect runs in Boss Dungeon) could be adjusted, and in ways that don’t significantly change the longterm analysis of Dragonite-over-time (aka. “the economy”).
(* - ironically, Dragonite is valued 25% cheaper than Diamonds. Just glance at the Boss Dungeon Offers and do the math yourself)