Personally I have seen huge drops an everyone of my 10 websites, except a couple.
Each website was relying on PBN to rank except one (and that one is one of the two that didn't face any drop). Affiliate websites except one, (and that one is one of the two that didn't face any drop).
From my observation, a huge thing they made with the latest update was the user intent. I was ranking on top positions for some broad keywords, and now the top spots were taken by stores that before weren't appearing on page 1. Indeed someone who search for example "Gaming chair" may not be interested to read reviews, but finding a store to buy the product.
Also I was outranked by other newer reviews websites that are using PBNs just like me. Probably they decreased the age factor? Probably they have more authority? I don't know but I think one of those two is the reason.