Moderation has probably meant that some details are missing here.

Maybe you could tell us (in general terms, without naming names or whatever caused parts to be deleted) what the problem is.

As far as I can see, you have not been selling a lot over the last year, so I am confused about what you mean about 'business model'.

How has ebay been taking it out of you?

The only thing I can think of that may apply (and it is conjecture) is that with your last sale, where a buyer didn't receive the product, they may have opened an ebay claim and ebay may have awarded them a refund, with the money taken from your account.

I think if you or anyone else is going to sell on ebay these days, you need to account for the fact there are some risks in any business. Your job as a seller is to get the goods to the buyer within your time frame, and those goods need to be as described. You not only have to do that, but you need to have proof of delivery.

If you miss out on any of those things, you risk losing any claim a buyer might open.

As a buyer, I feel that is reasonable. Ebay is trying hard to ensure buyers see this as a fairly safe place to buy, rather than a risky one.

Also as a buyer: I don't always take notice of feedback comments from buyers. Some buyers can be unreasonable. But mention of a lack of communication is a red flag to me. Your last buyer said their item didn't arrive and there was no  communication from you, so i presume that means they mesaged you and you never replied.

The thing is, you can reply to bad feedback and many sellers do, to explain what happened. 

It can be quite telling and can make or break whether a potential customer goes ahead and buys from you.

So yes, there is an element of risk when you sell on ebay but you can work to mitigate the risk with good packing, tracking and communication.

Are you saying it is eBay's fault you got neg feedback for non delivery?

Did you rectify the issue with the buyer?

No, I don't feel that way

I don't have any desire to waste my time and energy on fruitless pursuits when something does not go my way or I don't get attention

Any potential buyer seeing you have 80% feedback at the moment would hit the back button stat

I don't feel that way.

Others may do so... idk.

Your buyer who left a neg saying they did not receive their item may have some thoughts on your business model.