I expect nearly all foreign sellers have increased their prices to cover the tariffs. However, there are items selling for less than eBay says an individual will be charged in fees, so it's not just a you-pay-or-I-pay thing. Either eBay is exaggerating, or sellers are finding a way to get a better deal.

It's a minefield for eBay buyers who likely won't notice the footnote means their $5 purchase will cost them $20+ in fees. They now have something else to lookout for that doesn't show up in the table of search results. Something only in a small note on the item's product page. Something that might mean significant extra cost if you aren't careful when shopping.

I actually expect quite a lot of smaller foreign sellers have just stopped bothering trying to sell to the US, because the price plus the hassle isn't worth it. Large companies of course still will, with some price increase.