I think you're talking
I think you're talking exclusively about the Forester as this is the only model still excluding paddle shifters on some of the trim levels (at least as far as I recall).
I believe Subaru's view of Forester customers has been that they are generally older (especially since the front section of the doors double as hand-holds for getting in and out) and the Forester buyers didn't want anything complicated. So unless customers were getting the performance version (XT) then any unnecessary complications were avoided.
I started leasing Subaru's in '14 and for the longest time I wouldn't get my wife a Forester because it only had a "Drive" and "Low" mode for the transmission (which drove me nuts, even if I was only using her car once in a while). She ended up with a couple Crosstreks instead until we finally had to upsize to a '17 XT (wanted a 2.5 but got the XT because it had paddle shifters and they are indispensable in the mountains).
So I think keeping it simple was what took them so long to bring any paddle shifters into the Forester lineup. I believe it was the Black Edition in '18 that was the first naturally aspirated engine with a CVT and paddle shifters, but much like the 2021 Crosstrek Sport it was very limited in the options you could get and I remember considering it for my son, but it was more of a dumping ground for their old technology than anything else.
So even though every other model has already had paddle shifters in every trim for years, the Forester is only now catching up, but Subaru is still "giving the customers what they want" with certain trims and I think more than anything the company is saving money for as long as possible by not including them.