I can't comment on Newsbreak because I haven't tried it, but I do feel like Medium's distribution algorithm is broken.
Since August sounds about right. Both my views and earnings here have taken a severe hit since about August. Since October, for sure.
I'm still mulling over my options. I'm not sure my writing fits Newsbreak. I was thinking about Substack for a time, but they currently are out of bounds for me because of their open policies towards racist extremists.
I, too, do not use Medium primarily for money, but the views are important to me. And, strangely, I haven't been Boosted since October, which is by far the longest I've gone not being Boosted (or "Distributed," as it used to be called.) Boosting "boosts" distribution, but the system seems obfuscated and mysterious to me.