This is a tough subject to answer because there isn't a right or wrong answer, because for example you may have 50K loyal subs for 4 years but then suddenly lose them without a reason why, as people grow up they move onto other things, some people recommended keeping up with the trends and the times, but thats only if your interested in them sort of videos, if your just someone who does it for views and not the fans then you would lose support and gain hate. Best thing to do is to keep to your strengths a work on them, sometimes you can work on a weakness but its not something that should have all the spotlight as if it doesn't plan out your not too far deep in that project etc..