Halo has been ported to PC and steam.
But you’re right. Every console has exclusives, which indeed sucks. As an avid Xbox fan, I was hoping Halo would one day get released on PlayStation because I want other people to play it, too.
“Having something fun of your own?” There should be much better reasons to buy a PlayStation or Xbox than just the exclusive games. Xbox for example has GamePass. Nintendo has the switch that can be played on the go or at home.