tests like SAT, ACT, and some AP exams are using Desmos, yes

however:

- this means you have to fiddle with a popover window and can't always see the full problem (especially when the reference sheet is also online)

- you have less muscle memory and often take longer

- harder to multitask (you use paper anyways, and the paper to calculator friction is lower than the paper to trackpad friction

- trackpads on school computers are usually worse, which compounds the problem

- some specific functions just don't exist

essentially using Desmos is like using a physical mouse/trackpad, while using your calculator is like using VIM motions and keyboard shortcuts with a concave split keyboard. it's technically more intuitive and can help in certain scenarios, but it's useful to have both.

this sounds trivial, but it's not, especially on tests where you have about or less than a minute per question

ideally you have both a handheld calculator and Desmos though