The revenue from stablecoins and other projects is completely disconnected. The main source of income for Tether and Circle is not transaction fees, but the interest earned from reserves - with a current US Treasury yield of 5%, Tether easily earns $7 billion in interest annually. So you can understand that Polymarket wants to issue stablecoins. Who wouldn't be tempted by this low-risk business of making profits? Polymarket users' wallets lay at $1.2 billion, with conservative interest rates of $50 million per year even at a 4% yield. It is a trend for each platform to release its own stablecoin.