Samsung makes some of the fastest SSDs out there for gaming PCs and iPhones. They don’t use those in Galaxy phones either. On paper, UFS is slower, but in practice, you’d never notice.
My 2019 Galaxy S10 might take a second or two longer to boot up than my 2024 iPhone 16 Pro Max, but the difference isn’t enough to notice. Even running apps, there’s a difference but not one I care about. (iPhone screen is way better though, but that kinda goes without saying.)
Smartphones plateaued years ago but there’s a lot of money in convincing you they haven’t.