Really good question and its been interesting reading the varied answers and seeing the different motivating factors for creators.
The theme of my channel and my blog is 'See You in 5'. So the idea is its my personal 5 year journey as an ambitious 25 year old thinking about what I want from life, showing my progression, sharing thoughts, being creative etc.
I think more than a certain number of views what I want is to build a community. Thats why right now even though I check my subscriber count every morning, what I really want to initiate is engagement in the comments. I want to start conversations and get to know the 30-80 people watching my videos, and for them to get to know each other.
When I first started I envisioned See You In 5 being a platform where people can connect, be inspired, inspire each other and also have fun (i wanna do comedy skits and stuff aswell).
I invision myself going to schools in South Korea to talk to kids, I want to make documentaries on there and tell peoples stories. We all have so much going on in our heads and I want to explore it.
The goal is to 'Inspire a generation'. The other good thing for me is from a video aspect I can actively enhance my skills and start playing with my dslr again and editing having studied video production at university.
So in short my answer is what I would love more than 1 million subs for the sake of the number is 'Engagement' and 'community'. Kind of like Humans of new yorks comment section.
And thank you for this question because I think we can get so side tracked in the numbers. But the quote 'Remember why you started' comes to mind. (Bearing in mind people started for different reasons).
I think too many people are on YouTube desperately wanting to reach the heights of the greats. Me? Just fine being on YouTube. No matter if I have a 1 million or the 2 thousand subscribers I have now. I am having a blast.
If our channel reaches 1 000 000 subs and for this we used a variety of cheap (and sometimes quite frankly dirty) tricks I will feel like I just stole a candy from a small kid (despite my swollen bank account).
If we reach the same number of subs and on the way we entertained, educated and opened new mind vistas - than I we'll be much much more happy.