These lists of lenses are mostly the ones designed prior to their more modern designs, when they earned a reputation for putting out good lenses. There are a couple in there that were very good lenses for the value and newer designs (the more modern 70-200 f/2.8 Tamron jumps out at me), but most of the rest are legacy stuff from when the brands had reputations of being mediocre lenses at cheap prices.
Two incidental thoughts:
1) I wonder how much of their modern lens design sales are from EF mount lenses that are adapted to RF. I bet they sell more of those than Fuji mount lenses.
2) Since both Sigma and Tamron make lenses and lens elements for the larger OEM lens/camera makers, I wonder how much those commercial relationships cause them to be cautious in entering into direct competition with Nikon/Canon. We may find out in the future that lens elements in the $3k Canon lenses were produced by Tamron, for instance.
