As someone noted upthread, the install depends upon the knowledge, skill and experience of the tech, just as it does at Costco, Discount Tire or anywhere else.
I've had one set of tires mounted at Walmart, Pure Contacts bought online from somewhere.
They did a fine job and I had no problems with the work they did.
We all sometimes stigmatize Walmart for their selection of cheap Chinese merchandise and their overpriced grocery items, but we all love Walmart for the things it does well.
Oil for those who can't seem to plan a few weeks ahead for a drain?
Walmart is your friend.
Walmart TLE?
Good deals on oil changes with none of the quicky lube nonsense as well as good prices on tires and for mounting those bought elsewhere.
OTOH, I had four tires mounted and balance today for twenty bucks total, but that was just a lucky thing involving my job.