I have noticed the same too. It seems like most of these guys with big voting power only upvote each other 100% leaving little for the others. And some don't even upvote comments on their own posts, not even supporting their supporters. I do feel like the whales and dolphins are for the most part just building themselves up. Now don't get me wrong there are plenty of other big Steemians that do help out the little guys and upvote a lot of their comments. They are the one doing it right. But it does bother me with the small circles just upvoteing themselves with the 100% upvotes.
Cryptos are weird in general, we don't knowif they will go up or down and when than might happen. No one would blame you for taking some hard earned profits off the platform and into your pocket. And if prices happen to go up afterwards then great, don't beat yourself up for not holding out longer. Because we just don't know what will happen, like you said it could all go away in an instant if no one accepts Steem anymore or the trend could continue downward. I am hoping for the best though that things do change around here for the better of the community.