The ride might suck, but it's still new. Older rides can and should take priority for now. Simpsons and Rockit are both on a ticking clock and there's only so much budget to go around.
I know it seems like Universal is wasting time, but let's look at what's opening in this decade alone according to rumors.
2021 - Velocicoaster (IOA)
2023 - Villain-Con and Minion Land (USF)
2024 - DreamWorks Land, New Nighttime Show, New Parade (USF)
2025 - Epic Universe and three new hotels
2026/2027 - Rockit replacement (USF)
2028/2029 - Pokemon (USF)
Unknown, potentially later - Lost Continent replacement (IOA), Luigi's Mansion/Great Hall/Black Lagoon (EU)
That's a ton of investment in a short period of time, especially in USF alone. Supercharged probably just gets lost in the shuffle.