Limiting trading of 2-star cards and up is necessary to keep the game F2P-friendly

F2P players don't want to hear this but its true. We've all seen the posts of whales who have four crown Mewtwos, three crown Charizards, and 15 immersive Pikachus. What the reason that they spend thousands and thousands on each set? Because they are trying to find that one 2-star Sabrina, or that one crown Pikachu that they are missing to complete their set.

Now imagine the scenario in which devs allowed trading of 2-star cards. Instead of those whales spending multiple thousands to get the entire set, they might spend just a few hundred to get 95% of the set and then trade with other whales to get the one 2-star card they are missing.

Those 1% of spenders probably account for over 75% of the profits for this game. If those people significantly decreased their spending due to the ability to trade rare cards, the company would have to find other ways to supplement their income, likely by taking away some of the F2P-friendly features we've grown accustomed to.

Legends of Runeterra died because the game didn't make enough money. Marvel SNAP is not F2P-friendly because the devs are extremely greedy. PTCGP is in a great place right now because you can make every deck you want without spending a dime, while those who want to chase the high rarity cards can subsidize the game for F2P players.

TL;DR: Enabling trading of 2-star cards will dramatically reduce spending of whales, reducing profits, and leading to monetization of currently F2P-friendly features.