Some random observations:
Fanatics already authenticates and has the tools to slab:
It doesn't need to buy PSA, just expand its existing capacity.
PSA has been essentially shut-down for a year. It has distorted the market for slabbed cards and will continue to do so. I think part of the price surge on some sets is lack of additional PSA cards in the market. Pre-pandemic you could send in a standard-level order and have an expectation of getting it back in 30-90 days. Not ideal but not impossible. A business could establish a reasonable flow of inventory by staggering submissions. That has been impossible for a year and doesn't look likely again for at least another year. Clog up the supply chain and it clobbers the whole marketing machinery.
SGC is definitely the main beneficiary of PSA's backlog. If you follow postwar cards at auction you must have seen how many are getting into SGC holders now compared to pre-backlog. I never thought I would see SGC slabs on 1952 T Mantle, 1954T Aaron, etc. It is the only viable established TPG for maintaining any decent inventory flow or for having less valuable but slab-worthy cards encapsulated for auction.
CSG is about to ruin its timeliness reputation with its nutty deal with eBay (see the other thread).