It has drawbacks, like if the person doesn’t have $10 or they complain that they’re being charged. But a) is unlikely since most people who are that poor aren’t donating money, and b) is hopefully unlikely if you make it very clear how the payment system works and that they can get refunded if they cancel early.
They keep degrading the pooling and/or threatening to remove it entirely.
That is, instead of $3/month you do, say, $9/quarter.
Whole reason why any service is paid monthly is because it's just makes more money over customer lifetime.
People do month to month because they don't know if they'll find value in it, it's totally no commitment.
Asking to think if I'll still like this creator in 3 months requires actual thought... and $9 feels like money whereas $3 just doesn't.
If I were donating to creators on different platforms, it would be 20 transactions, each with a fee of around $0.30, so fees would eat 30% of my donations.