its impossible for us to advise if you can everyone needs to earn a different amount before they can go fulltime
I am a fulltime youtuber (and stream twice a week) i earn around $1,000 a month from ad revenue, $2,000 from patreon and about $1,000 a month from twitch streaming twice a week
so the people suggesting you need hundreds of thousands of subscribers are not actually right ( i have 32k subs), it very much depends on your community, your niche etc
so yes, doing it full time is still very possible, you just have to work your butt off for a long time earning basically nothing to grow a foundation
i have been a youtuber for 2 years and 3 months, and for the first maybe 18 months i earn't a few hundred dollars working 40+ hours a week, now its 60+