Well... each social media is different, there is no magic trick nor formula that would guarantee you to be popular in a short amount of time or get unrealistic numbers of followers in a few weeks.
Most of the time is having consistent appealing artstyle, interesting topics or themes, posting around 2 times a week, making either fan content or original content, following trends, but I believe that what really gets an artist out there is when the artist is the one engaging with others, be it fellow creators, be it engaging with a fandom, or a follower, being part of a community and seeking to engage with it without ulterior motives or conditioning support.
I gotta ask you, and I know is a though question but nothing to feel offended about, is a genuine question I also ask myself daily:
Why, from the billions of people that post art, someone would exclusively choose you?
And this not only for commissions, it can be for following, for supporting in any way. Like, what makes you shine? What is so interesting about you that would be a reason to follow you?
I believe you can get feedback and any place, especially on facebook if you add such a line in your group post, you can share your work anywhere and enjoying art is mostly based on what you do more than in what you get for doing it.
I gotta ask why are you desperate for recognition? Or to increase your numbers? What do you think is gonna change?
I've got stuck on the same numbers for more than 5 years now, people come and leave.
Facebook, Discord and Tumblr are my favorite places, mostly for when I'm in a fandom and I share content like AUs, silly fanarts, cursed drawings and similar.
On Twitter I mostly engage in the Vtuber community as a member of a group, I make artwork but mostly the stuff I do and that involve friends is what gets engagement there.
Instagram is the sample of how nowadays people don't comment as much but give likes, regardless, I don't expect engagement through there, but sometimes a nice comment or more likes than the average pop up.
Then Youtube and Twitch, is great for engaging with people that is starting to draw or if you want to chat with someone as you work, personally I believe I would do "better" and get more people if I used a mic, but I'm comfy using OnStream Chat.