Reading some deets:
Liberapay - does not take a cut of payments, the service is funded by donations to its own account. However, there are payment processing fees. The fees vary by payment processor, payment methods, countries, and currencies. In the last year, the average fee percentages have been 3.1% for the payments processed by Stripe and 5.1% for the payments processed by Paypal.

Ko-fi - No fee for one-off donations (editorial: FUCK), 5% platform fee to use premium features/become a Ko-Fi contributor (basically to give Ko-Fi a cut in exchange for premium Ko-Fi features for TheDude and co)