Postings like this appear frequently on this forum and there is no definitive answer. There are a lot of things that effect sales not only on eBay but on other venues and forums as well. What you are selling, pricing, shipping cost, competition all impact sales either positively or negatively. Then there are external factors like the economy and the global market that come into play.
Yes sales in some areas have dropped off dramatically after the post COVID surge and a lot of people have returned to their pre COVID shopping patterns which includes obtaining commodity type items from B&M stores. I buy VERY little on eBay simply because I am in a large metropolitan area and I can find items cheaper at B&M stores. I can look at the item, try it on, inspect it........... before I buy it, take immediate possession of the item and generally return it easily without any problem if I discover something wrong after I have gotten it home.
Over the last several years the percentage of eBay's foreign revenue/sales has gradually increased to where it is now over 50%. A lot of this probably has to do with items coming out of foreign countries that are able to undercut the market for one or more reasons.
Some of it also has to do with the items eBay prohibits and restricts, the VERO program, etc. EBay basically forced me, although I was already heading in that direction, to diversify across multiple platforms and venues and eBay now constitutes less than 20% of the merchandise I sell. There are a multitude of factors that have contributed to this. So yes my eBay sales are a bit slower than normal but I am doing fine on the other platforms and venues.
