For a long time, we subscribed to big channels. Big channels never subscribed to us.
Big channels are mostly only there to farm views, and it doesnt matter how much comments and likes you give them, your small channel wont grow by much.
Right now, there is a different kind of movement on YouTube. Instead of small channels supporting big channels, small channels support each other.
You can find comment sections specifically meant to achieve that all who comment subscribe to each other there.
I realized that only by subscribing to many small channels will my channel grow.
I place my subscriptions to be seen publicly. I subscribe and comment to 100 small channels per day, and many subscribe back. I gained about 80 subscribers in past week.
For 2 years, I was stuck on 80 subscribers, and now I have over 160 there. Gaining 80 subscribers in a week is a big deal. Its 300 subscribers per month then in future.
I did also change a lot about how I upload my YouTube videos.
Now I use words people most often search for on YouTube as video title. I also tend to copy whole title from some other very popular video of other people.
I also learned more about using video tags. For example, you can use repeating tags by changing letters to capital: "anime, Anime, ANIME, AnimE...".
I also learned about importance of uploading your video as private video. After uploading, you edit a video a bit and watch it few times too. Only make video public after a day or two when you have 10 of your own views on it and done all editing. Dont watch your video multiple times in a row. Watch once or twice every hour. After making video public, watch it also once or twice every hour.
Also, in YouTube studio, check which videos have highest likes, highest subscribers, highest views, and highest watch rate. Post more of such videos, less bad ones.
Also, comment and respond to all comments, give likes too.
All these strategies helped me increase views and subscribers too.
But also, quality of content matters.