I have passed 1000 subs, but it was a long journey. I uploaded my first video in December 2012. But back then I didn't upload to grow or anything, I uploaded videos for a group of friends without any intention of other people watching the videos. I uploaded my first "public" video not just intended for my friends 30 October 2015. According to social blade I had 20 subs early December the same year (as far back as social blade goes for my channel). From that point it took me about 2.5 years to reach 1000 subs.
Back then I was a lot less serious about YouTube. I didn't use thumbnails until mid 2016 and when I started using thumbnails they where pretty crappy. All the way up to pretty late into 2018 I used to take long breaks from content creating where I didn't post a video for months.
Late 2017 I started to get a bit more serious about YouTube, trying to get better thumbnails, reading up on stuff, seo, titles, tags descriptions and from late 2018 I have been creating content pretty constant without longer breaks (had a 3 weeks break at the most) and It has had a good effect on my channel. I'm still a small channel, but while 0 - 1000 took me 2.5 years, 1000 - 2000 only took me about 9 months. Going to be intersting to see how long 2000 - 3000 will take me, hopefully I can keep on improving and reaching that even quicker.