If literally everything else about the systems were exactly the same or equally appealing, then yes. But if you had to rank the factors that you'd consider, how far down would rumble and haptic triggers be on your list? How many people do you really think this will be the deciding factor for?
Are we talking consoles or games? If you have both systems - then quite I few. I know several already that are going third part for ps5. The frame rates and performances are nearly the same. Quick resume is is similar (and better) to the removal of the "logos" and activities on the ps5.
As a console selling point - maybe. I'd probably put it under games. Exclusives mattering the most, and then gamepass.
If someone is only buying an xbox for halo/forza/Gears then yeah that won't do anything.
But if GTA 6 takes full advantage of the dual sense on the PS? Hell yeah that will absolutely affect sales of consoles.
If Sony is "counting on" it, I would assume that they're talking about consoles. But even among for games, I don't think it's near the top of the list for many people. Performance would likely be at the top. I'd imagine that for multiplayer games, what other people play on (and cross platform play). For games that are available on Switch as well, there is portability to consider. And, for people with a gaming quality PC, they might consider that.
Controller is definitely more relevant to games than console, but still not really going to top my list. And this is also assuming that the Dual Sense features actually make the controller better, which I'd have to try them both to figure out. I generally find XBox's controllers way more comfortable than Playstation, so that would have to factor in.
As for consoles, the dualsense features (microphone, HDrumble, adaptive triggers or whatever they use), are pretty low on my list. Exclusives would come first, then services like Gamepass/PSNow, then hardware specs, then probably what more of my friends have, then price, then probably the controller as a whole, but not necessarily limited to those specific features. The quality of rumble/trigger resistance is probably a bit further down after overall comfort of the controller, backwards compatibility for hardware/software, back catalog, and maybe the OS. At best it would be like my fifth consideration, but it would be a really distant fifth.
As for GT6 w/dualsense features being a significantly better system seller than GT6 with not as good dual sense features... I'm highly skeptical.
GT6+Mediocre Dualsense Use- Nah.
GT6+ Great Dualsense Use- Here's $300+.
Doesn't add up to me.