Only mentors can reply in this part of the forum - you would get more responses/discussion in 'selling'.
However, my view is that it is appalling that this is still not sorted out and Simple Delivery is still not working properly when you list an item.
There are workarounds etc. but, given that 6th August seems to be the final deadline for Simple Delivery to become mandatory for private sellers across the site, and there is no straightforward way to list oversize items, I can perfectly understand why sellers are cross and frustrated.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)