Regardless of whether MST is antiquated or not, magnetic readers are insecure technology. They allow for hackers to install stripe reading technology and steal credit card information for one, and there are other disadvantages as well. At least with Samsung Pay MST, that information was masked making it possible to have a more secure option when presented with a vendor who was still using that antiquated technology. With the removal of MST, that is no longer an option. For those of us who live in rural communities with tons of mom and pop stores, that means we will be forced to once again swipe actual cards instead of using a more secure option.
I would LOVE it if the industry stepped in and forced all vendors to use chip readers. But, they do not.
I will not lie, I seriously contemplated not upgrading my phone over just this issue. I went ahead and did it anyhow though. However, the removal of the MST now gives me more options to think about on my next upgrade. Almost ALL phones have NFC enabled pay systems.
With the loss of Samsung Cloud storage (Which I now use a local backup option), the loss of MST, and the loss of some of the key functionalities of Smartthings integration (which I have replaced now), I am losing my dependence on Samsung. I am sure I am not the only one.
So, the loss of MST is a loss. However, the new freedoms it unleashes may wind up being a bonus in the long run.