A large increase in traffic to and from mixers, and a large decrease in traffic to and from centralized exchanges. I don't find this surprising at all. As time goes on, centralized exchanges are more and more turning themselves in to self appointed judge, jury, and executioners for people who use them. They track the movement of your coins long after you withdraw them from the exchange, and they look back at the history of your coins long before you deposit them at the exchange. If they don't like what they see, your account is locked and there is nothing you can do about it. If you perform some arbitrary "suspicious activity", your account is locked and there is nothing you can do about it. If you deposit too much too quickly or withdraw too much too quickly, your account is locked. I'm sure that plenty of coins that have touched a darknet entity have been locked, frozen, or seized as soon as they touched a centralized exchange, but this isn't just the case for darknet entities. There are centralized exchanges policing perfectly legal bitcoin usage, such as to and from casinos and gambling sites.
We will continue to see the popularity of mixers and other privacy enhancing techniques such as CoinJoin and PayJoin increase as time goes on.
I mean, I hate Centralized exchanges as much as the next guy -- but I don't think they have much of a choice if they want to stay in business and not be shut down. The only reason that these companies are doing these things -- such as tracking your coins a few hops back, sending notices regarding using mixers / gamblign, etc -- is because this is what the government that their licensed under wants them to do.
No company is going to want to waste extra resources just for the fun of it, they're going to do it because they were forced into doing this sort of thing.
I do think that decentralized exchanges will grow at some point, but people need to learn the in's and outs of using crypto first -- and I don't think we're there yet. Using an exchange like Gemini, Kraken, Coinbase, is so much easier and quicker to use then trying to get bisq to work (in the eyes of a first time user)