if you wanna grow an audience, it's a good idea (although exhausting) to start posting on multiple platforms, because different people get successfull in different places and you can't really predict which one will be the best for you, which algorithm will favor your posting style
at the end of the day what gets your art noticed is the quality of it, but i've noticed that all successful artists have a niche, all their works are done in the same established style and look good together, and that makes sense, someone sees your art, likes it, goes to your page, sees tons of similar art, they'll definitely subscribe, and if you do lots of different stuff and the pic they liked was sort of a one-off, they'll leave