Why would they have to give up control? They’d be like the artists selling the NFTs and they’d likely come up with a model where they get X up front and Y% on resales. They’d have to figure out the amounts so they’d maintain the revenue or increase it since more people might pay for an extra 5 skins if they knew they could also resell it later.At this moment? Not really. Axie was the first compelling PtE game and it's not anything special. However, it's awoken the industry, especially those in crypto.
While it "wouldn't be very hard" for games to incorporate NFTs doesn't mean it's going to be easy or that it can happen quickly. You're asking a centralized company who makes a lot of money selling in game assets (that was Fortnite's whole model) to give up control and its revenue stream. Some will be quicker to act than others, but we're already seeing some dragging of feet by companies such as Valve.
Your comment on the not compelling part is what I thought. Axie’s market cap is about half of Take Two’s and Take Two has thousands of employees, hundreds of millions of customers and many games like GTA. I know I’m not supposed to compare market caps but I am because unlike currencies, a coin built around an online game isn’t all that intangible.