As a mathematics educator at a community college I fully agree with your sentiment. However, faculty tend to dislike the use of smartphones or tablets as calculators since one can have notes on the device and use the internet. I personally have banned all calculators, notes, and tablets during quizzes. I require my students to Mathematica for take home assignments. They do not pay extra for Mathematica as we have a site license.
The TI-84 should not exist at all. It is underpowered and way overpriced. I think it is still used since students pay for the devices and not faculty. Institutional lethargy is at play.
My wife teaches high-school math. Course material and textbooks contain step-by-step instructions for a TI-83+, and they have class sets of the darned things.
This zombie hardware is thoroughly entrenched.
At the very least if the lessons targeted MatLab, we could see OSS implementations like Octave. But all the TI emulators still rely on pirated TI firmware.
The TI-84 should not exist at all. It is underpowered and way overpriced. I think it is still used since students pay for the devices and not faculty. Institutional lethargy is at play.