Don't you rather believe that the reason why Reddit's user experience is worse is that Reddit has economic incentives (e.g. better options for ad placements; advertisers prefer this US; ...) to do so?
Its like no one involved in the design used Reddit regularly. Reddit's best quality was the way it made forums work at scale, but they tried to copy content feeds at the cost of community. That's why old.reddit, Apollo, and RIF are the better experiences for using Reddit - you can engage in community more than just consuming memes and gifs. Certainly a part of that is incentives, but the job of good leadership is to push back and point out that Reddit isn't Twitter or Instagram.
And even if they wanted to make it like Twitter or Instagram they really screwed the pooch by having terrible stability and performance.