I don't mean the usage of Apollo in particular, but my understanding from what I've read is that according to some metrics, almost 50% of Reddit have gone dark, partly in support of Apollo. It's already the unofficial alternative to Reddit, except also kind of being Reddit at the same time.

Correction: I did a quick check, and around 40% went dark according to this source, so not quite the 'almost 50%' that I proclaimed: https://twitter.com/aakashg0/status/1668107416490192897