I think there is a lot to take from this one, many points already made, but I think the biggest thing is that Marvel has remained virtually the same scale for the last 20 years, while Vintage/3.75 inch are seen as an "old fogey" type of line. Let's face it, people like us who visit collectors forums are a dying breed, and younger fans/collectors have moved to or started with the 6 inch line. They're more concerned about getting 6 inch style Clone Wars and Rise of Skywalker figures than they are getting vehicles we've wanted for 30 years.
That’s a really interesting point, and probably a longer discussion thread, but something I’ve been curious about too. Really there is no way of knowing for sure, and it doesn’t impact what we are interested in one way or the other, but are the older school fans and collectors truly a “dying breed” (for lack of a better term). The most recent Black Series Fan Choice Poll really started me thinking about this again. Cody is a fine choice, sure, but I was a little surprised he won. I guess those polls have often been a little wonky, but that coupled with a lot of what I see on social media really points to the “Clone Wars Generation” inheriting things now. Not that I have a problem with that, it’s just interesting to me.
I basically enjoy most to all that we see from Star Wars, even if I’ll always look at the OT as my Star Wars in particular. I enjoy Rebels, CW, PT, ST, Solo, R1, and definitely the Mandalorian. I’ve just noticed as my daughter moved into middle school last year, a lot of kids that age (and older), really have next to no idea about the OT stuff outside of “Darth Vader” “Chewbacca”, and “Stormtroopers” unless their parents are fans. Heck, I work with a number of people in the 20-30 range who haven’t even seen those movies. I do wonder if 3 3/4” is indeed the “old people scale”, because you see very little of it. Some Fortnite, and Spinmaster is trying some stuff with DC, but that’s about it. Anyways, just getting old I guess...
Back on topic, the closest 6” scale approximation to the Sentinel I can think of is something like the Rancor. That would be crazy to see.