The solution i find about subscribing channels;

I am selecting "Don't recommend channel" for subscribed channels so i see them only in Subscriptions page, i am afraid that Youtube can see it as i am not interested these channels and topics but i didn't see any downside with this method.

I am also unsubscribing frequently posting channels and bookmark them if i want to visit them later so my Subscription page don't have spam videos.

Also removing one time watched uninterested-topic videos from history may help algorithm.