You'll see eBay collecting sales tax on shipments to additional states as the year progresses - Iowa effective February 1st and Connecticut effective April 1st, for example.
The Supreme Court ruled in favor of South Dakota in June 2018, which removed the requirement that certain retailers have a physical presence in a state in order for that state to impose sales tax obligations on them. Regardless of where the seller is physically located, states may require sellers to collect applicable taxes on their sales.
Several states consider shipping & handling charges to be taxable, Minnesota and Washington being 2 examples.
Is it fair? Personally I don't see any reason to be upset - we should expect to pay on purchases made in states that have a sales tax. And note that South Dakota doesn't have a personal income tax - obviously the state needs some source(s) of income.
There are incredibly complex criteria for determining tax rates in cities, counties, townships, parishes, transit areas ... well, let's just say it would be a nightmare for every mom and pop eBay seller to collect and report sales taxes in several states!
Fortunately for us Sellers, eBay is treated as a "Facilitator" of those sales and has the responsibility of collecting and reporting sales taxes charged on our sales.
Don't expect sales taxes to go away!
Dennis