Limited supply, high demand, deliberate scarcity, influencer hype, and the power of nostalgia all play roles
Flying Dethrone (Whenever this creature attacks the player with the most life or tied for the most life, put a +1/+1 counter on it.) Whenever Scourge of the Throne attacks for the first time each turn, if it's attacking the player with the most life or tied for most life, untap all attacking creatures
Of course, it helps a lot if you know which cards are worth looking out for, or which ones you should try and pick up for your favourite deck
That creature gains trample until end of turn
And even if you don't go crazy, sac a bunch of tokens, get a bunch of Blood Artist triggers, and what have you, you can still easily end up with a pretty big flyer for four mana or give/proliferate it counters through other means
At the beginning of your upkeep, for each color, put a +1/+1 counter on a Dragon you control of that color