OP, If you would like to see for yourself how eBay comes to have so many listings and why I would never want eBid to be like eBay, please search for Ford Mondeo Mk3 Headlight on eBay UK using the general search field. Assume that you are looking for a replacement headlight unit and not for a replacement bulb. If you set the search parameter to lowest combined price and postage, you will find at the front of the search pages and pages of listings for headlight bulbs. The specification for the standard headlight bulb for a Mk3 Mondeo (Mk3 = Mark 3 or model Series 3) is the same across all Mk3 models, irrespective of the model type or the trim type or the engine type or the transmission type etc. Yet many of the sellers of Mondeo headlight bulbs will create separate listings for the same bulb according to engine type or model designation or othjer variation. They do the same even if they are not selling standard specification bulbs but uprated bulbs. Rather than have one listing advising which Mondeo models a bulb fits, these sellers bloat the number of listings for headlight bulbs needlessly and to the point where there are so many of these duplicate listings that it is extremely time consuming to find listings for headlight units. Some areas of the eBay vehicles parts area are effectively unuseable because of all these duplicate listings. So please do not assume that high numbers of listings on eBay means a high quality buyer experience because it does not. Much better a site that is convenient and useful to use for buyers than a mega site that is out of control and is not convenient to use.
In my example above, please see how long it takes you to find yourself some headlight units that you might consider buying and find out how easy it is for you to compare your short list of potential buys. Then you will understand what high numbers of listings can mean.
The eBay situation is not helped by the limitations of the eBay search engine and the fact that the eBay site outgrew the search engine capabilities years ago.
If the eBid members who keep repeatedly posting these kinds of threads to the eBid Forum want eBid to be bigger, rather than spending time on the Forum maybe much better that they put their energies into listing more items themselves and ensuring that there is sufficient quality description in their listings so that potential buyers know what is for sale.