Maybe the users are too blame as they measurably prefer websites with modern UX and don't really care about latency over a few hundred milliseconds.
If your school uses gsuite (which they likely will given free stuff and integration), you can't choose not to use gsuite.
Same way as dev employees are forced by companies to prioritise features over optimisation.
Yet they keep on adding more and more crap, soon Gmail is going to load for over a minute..