Not true. Visa and Mastercard don't make the bulk of the commission. When a merchant pays a standard 2.9% + $0.30 fee on a credit card transaction the issuing bank gets roughly 1.5-2.5% for interchange, which is the bulk. The processor or acquirer gets anywhere from 0.2-0.5% and the card network gets only about 0.1-0.15.

Also, PayPal does not lower a vendor's commission. If they pay with a PayPal cash balance, PayPal still charges the merchant a premium flat rate (often 3.49%) and simply pockets the entire spread. They don't pass the savings down. And consumer's don't have a Stripe account to pay from, Stripe is probably aiming for PayPal wallets via this move.

Upvote because AFAIK this is true. Not sure why your comment was downvoted to dead just a few minutes ago.