CSGO already has like 34 different weapons according to Google compared to Valorant's 17, so that really isn't a problem.
New maps get released all the time because its community driven. And decent amount of those have even been added to competitive mode. There's like 13 maps in active competitive mode pool. Only reason why you see so much of Mirage, Inferno, Nuke, Dust 2 etc is because they are by far the community favorites.
New granades would be cool, but I don't know what they could add without ruining the core mechanics. And smoke changes completely change how they function and will also change how HE granades are used.
and they have multiple characters models for you to buy, but yeah change to the default ones would be cool even if they are iconic models.