The RED Line (Probable Spam) is distorting the Chart so the BLUE Line (High Quality Events) doesn't look as impressive as it would by itself.
If you hover over the blue dots you will see that they are generally trending higher since Jan.
https://void.cat/d/FitenTcN7CENFyFN2TycGR.webp
https://void.cat/d/QDwLF6kMP1M8NSd5NqkzdV.webp
#[2] uses what he calls "Trust Rank" to determine 'High Quality Events'. He has added information about it here: https://trust.nostr.band/