“credit card acceptance fees have gone up in the US since the pandemic” and the reason is fascinating!
It's not Visa/Mastercard being greedy, it's an arms race by banks to produce higher tier and more exclusive cards to capture more interchange revenue and fund more generous rewards programs! (See: Chase Sapphire Reserve, which got an entirely new card tier added to the interchange rate table so Chase could compete with Amex's US rewards program.)
A random observation I will make here is that there are two ends of the market that are expensive to serve in banking, the very top end and the very bottom end.
At the top end, customers are expensive to serve but bring in revenue. At the bottom end, customers are expensive to serve and, despite what you might think, often don't bring in enough revenue to pay for that service.
As a society, we shouldn't want this to happen and for people to leave the regulated banking industry. The alternative is, well, “alternative finance”, which means the lower end of the economy pays extortionate fees to what rounds to payday lenders and cheque cashing businesses with extra layers.
When money leaves the regulated banking industry, society bares the cost of increased difficulty tackling financial crime and tax evasion. This is why the UK and EU has universal basic banking.