Disconnecting from social media was part of a larger effort to remove distractions - around the same time I also deleted steam and cancelled my netflix account. The wealth of time this left me to focus on self-development was absolutely critical to figuring out how to 'take my computer hobby pro'.
My guess as to 'why it worked' is this; in those moments when I'm sitting around with nothing to do, there are no easy outs (facebook/insta having been the easiest and lowest-drag options for spending time, they were the biggest offenders) so you sit with your discomfort at being underoccupied for a moment, get frustrated, and pick up a tutorial, technical manual, or start googling around for answers to a question you have.
By no means was it "deleted facebook and productivity gods smiled upon me, bestowing me with champion focus and a fulfilling career", but without the disconnect, I'm confident I would have failed. The times when I would be doomscrolling also turned out to be the times I had the best bursts of inspiration, besides being the entry point for more focused bouts of actual, real work.