People should give feedback to channel owners that overuse announcements. 

Send a DC. Tag them in cast.

Co-create the community you want it to be.

And if they are not receptive, leave / unfollow / create a new one.

Stop thinking of channels as canonical topics.

The relevant number for channels is now members, not followers.

Channels are now much smaller than they used to be.

If you genuinely believe a channel should be run differently – there’s never been a better time to start a new one.