Ebay has never had a fee structure of 2.5-3.5%.

Fees have been approx 13.4% for donkeys years now (with a slight variation, depending on which category you sell in)

Ebay is about 10.4% and Paypal was about 3% approx. All that has happened is that is that Paypal has been dropped in favour of Adyen and the combined fee is now taken up front, instead of getting a monthly invoice. The nett balance is sent to your bank account.

All the fees are outlined in the sellers guide. If you're smart, you can structure your listings to take into account the selling fees.

Ebay is around of the cheapest - Amazon fees are probably about 17% in comparison. All of the other big platforms work on a Managed Payments system - Ebay is actually late to the party.

I highly suggest you get signed up for the new MP system and become validated prior to any listings. There are plenty sellers who delay signing up and then come to the forums in a complete flap because they've sold something and only now are they realising that they have to submit proof of ID such as a drivers licence or passport, which they either don't have or refuse to get. Then they're 100% stuck as they cannot be validated.