Why is digital technology used almost exclusively as a PC based tool or resource in education?

Digital technology that works on PCs is more common since that is what everyone has. Software and its licensing is costly and upgrades to Mac or other machines is beyond budgetary abilities at the present time. In the past, Apple and other companies provided these products at lower cost, but not sure that that is true any more.

Digital televisions are commonly available, but the older models still work fine. Schools do not have the money to replace them. But, the additional clarity is not integral to the lessons being taught, either.

Answer

Unfortunately some workplaces have the attitude of either you use what technology we have or your replacement will, I hope education is more enlightened but Education is policy driven so if policy says you will use PCs - personal computers - to be PC - politically correct then that's it folks.