So much to unpack. Okay, if they make psionics into magic and use spells, I am just going to do a homebrew of my own or find a good third party set of rules. Part of the point of having psionics is to have a set of supernatural powers that has a different feel to it than magic and that means its own mechanics. I think just not wanting to learn a new set of mechanics is just lazy, put some effort into your game and be adventurous. Read the novel "Master of the Five Magics" by Lyndon Hardy. He has five classes of spellcasters, each class has a completely different set of magical laws and mechanics. There is no reason we cannot do the same thing in D&D. Throw in True Name magic, Pact magic, and Shadow magic from the "Tome of Magic", just update the mechanics. The 2E rules were amazing for the time. A skill and feat based psionics system with tangents and psionic harbingers an constructs could be done in 5E with the benefit of the updated skills rules and saving throws. Take a look at the Force rules from the d20 Star Wars game. Add telepathic combat and you have a psionics system.