The "nobody visibly cared, then some people cared more loudly, then everyone cared" pattern exists in essentially everything.

Climate change, opioid addiction, police murders, genocide in China, microplastics, childhood obesity, #metoo, whatever other thing.

That's just how society works. There are a billion different things happening every day, at any given moment some are gaining attention and some are losing attention. Everybody will care about the most popular one for a while, some laws might get passed or someone might go to jail or get elected or give a speech, and then it'll fade from the mainstream news and daily conversation will move on to the next issue.

This isn't some coordinated conspiracy, this is the pattern of how literally every issue ebbs and flows in attention.