Could have to do with the particular content ideas. Not bad ideas to get views from existing subscribers I guess, but you might want to consider some different, more searchable ideas.
Notice how your most viewed uploads were much more specific in the topic than what you've uploaded recently. Those were good videos to bring in new people. I think you should go for more videos like that. I know it's hard to get "outside the box" with CSGO content. Have you ever tried any weapon skins videos?(top 10 skins for x weapon, top 10 skins of a certain color, best skins under 2 dollars... just examples) Or stuff like expanding on that video you did about how to get out of silver easy. Sure it didn't get tons of views, but you got 10 likes so clearly people liked your advice. A few more active CSGO subs for each video and some passive search views can add up over time.
Just some thoughts, if you find something that works, keep doing it.