It is a scam in so far as blockchains, etherium, nfts ... are a scam, including any "games" and "communities" built around selling it to people. Pardon, building engagement within your community. The underlying principle is a pyramid scheme with making people addicted to spend money in the hopes of gaining money. Much like shares on stock market. But with hot air instead of part time ownership of a company producing actual real things.
Ubisoft dabbles with blockchain games, so that might be the connection.
leveraging their user base
Translation: milking them dry.
Any play to earn "games" should be forbidden, or rather treated exactly like gambling with real money games.