imo they should just follow the CS:GO formula, make it free to play, or dirt cheap (10-15$) with battle passes, seasons, new maps every season, map rotations every season etc. and if they want release some single player content every so often as a paid DLC for those who want it
to me the "buy a new game every year for a full price" principle just feels old and outdated
they alrdy do a simmilar thing in china i think with CoD:Online