Can you make it in the industry if you only use FOSS software?

I made a successful kickstarter and $5000 worth of commissions purely on mypaint, but I recently upgraded most of my tools and process and as a result use Krita more often (better editing options)

So as a hobby it doesn't matter, but for an industry it most likely matters, most studios don't want to deal with lone wolfs so you're better off just learning PS unless you're working with linux devs or some shit

Try krita.