It's a very strange MO for the company to always side with the buyer. Without sellers they have nothing
You can win as a seller, but only in a "clear cut" situation.
For example. I sent an item and I used RM Special Delivery - I always do on items I sell for £50+.
This is a fully trackable service as per EBay instruction.
I've twice had people claim that their package failed to arrive. I showed Ebay I'd used the trackable service and the track showed it had been signed for.
Cases dismissed in favour of seller.
But as soon as you're in a "his word vs your word" situation with no way of really proving, then the buyer will always win.
But they settle the case without hearing both sides of the story.
When someone emails me to say they cannot set something up and then an hour later raise a return because "item is damaged" I'd like to let Ebay know my side - I wasn't asked, closed in favour of buyer.
Very basically, as a buyer you've got 30 days to raise an issue. So buy whatever you like on Ebay, anything. Use it for 21 days worry free. If you have buyers remorse, don't want it any more, etc, just raise a return and say "doesn't work" or something similar.
9 times out of 10 the buyer will win - you'll get a full refund.