I have been battling
Therein lies your problem.
They couldn’t care less
They do care. However, they can't adapt their modus operandi to every single seller. Some will stay, some will go and others will come.
It's the same with our customers. Some we just can't please and they wander off to the competition. We do care but are just not willing to accommodate some of their requests.
#1
We have never been treated like dirt, even when our eBay fees were only $250/month.
Why do you get threatened with suspension "all the time"? Surely because you are violating policies. Phone PS support and they will tell you what the "warning" is about.
#2
It's a mere assumption and, besides, what difference does it make?
Why doesn’t eBay implement a DSR
Run it by them. You never know; stranger things have happened.
eBay will lose approx $3,600.00+ a year
Not necessarily. Many items sold on eBay are unique and if not purchased by you, will be bought by someone else. A competitor leaving a marketplace is often an opportunity for someone in waiting.
Cheers
Bernie