I agree (with you, disagree with what you quoted ). I’ve ordered a gig from a seller who had about 80 orders in queue for the gig I chose, and orders for other similar gigs too, above 100 in either case, and a pretty low delivery time.
As I’m a forum regular, I mentally was prepared for a longer wait but communication was very fast and also the delivery was extremely fast, early next day, actually (and I think what I ordered might even have been 2 days delivery time).
My conclusion is that sellers with many orders in queue either deliver only/mostly things they can do very quickly (if now because of long experience and expertise or other reasons), or have/are a team, or have also custom orders with longer delivery times in their queue, and, as Jon brought up, good order/time management, workflow and such.
Personally, I probably would choose a seller with not quite as many orders in queue if I need something “serious” that I know should take a seller some time, or might need much talking, perhaps over several days, depending on timezones, etc., to be sure to get what I need
So… It depends. It will attract some people and deter others.
Plus, as catwriter mentioned, many buyers won’t even notice.
I don’t see an issue though from seller POV. If you have a long queue and can manage it well, great for you. If you haven’t, well, then you haven’t. Try to do something about it if you want it.