Tons of possible factor, base on my observation this could be because of the advertisements and promotions there are a lot of influencers recently taking profit in trading and they keep sharing and promoting different trading platforms this will be serve to them as a help and realizations that they can also be rich like other people do so they grab the chance to take theirs, also considering the different form of earning such as airdrops, meme coins, and etc, this gives an impact people now engage with the crypto space at all, I gues considered as last is the trading events of the casino because they are offering giveaways and coins to those newly registered and active traders with a prize pools.
Basically there is now an incentive to make people join bitcoin, which didn't existed back in the day long time ago. Bitcoin was an individual thing, you got in if you want to or not, it was up to you, and nobody really cared, I mean we would be happy, but that's it.
Now there are exchanges, casinos, ETF's and many other business that is around the crypto world, so it looks like it was something that would benefit the people. So that is why I think it is clear that those companies spending countless amount of money on marketing, ends up helping people out and making it more known and getting more people in the door. That seems like the most logical reason that I can think of why there are more traders these days.