I love small channels! I'm always excited when I find small channels that are related to the content that I'm making, and/or my favorite hobbies. I think a lot of the people who use YouTube regularly are happy to support small channels that they like.
Big channels are..well..big....I think humans tend to like to join in on things that have already been approved by a lot of people (at least, that's how I am with new electronics..lol!). Plus, large channels already have a lot of searchable content made. More videos mean there is an increased chance of having the content viewed from a search. An increase in search hits creates an increased chance of videos being shared...I think that's where a lot of the "snowball effect" thing comes in.. Also, even if the video isn't one that the viewer wanted, the "related videos" on the right-hand side might show a video from the same large channel that interests the viewer.
I think that smaller channels might not have their channel's videos in the "related videos," since there haven't been related videos published yet from the same channel....A lot of popular search hits for a small channel's video might make the video end up as a "one-hit wonder" if there isn't any additional related videos to watch..
But I do think that large channels and small channels both have to work equally hard to sustain their audience's attention. If anything, I think more pressure is on the larger channels to aim to grow or sustain massive view rates.. YouTube is just fun hobby-time for us small folks. I don't think there ever will come a time when things "get easier" due to an increased subscriber number, but I'm a small channel, so I really wouldn't know. ^_^;;