Events also play a role, I agree, but the bigger one is the KYC requirement even now. When Bitmex started enforcing KYC verification. Bybit was still not strict with theirs, thus that why the volumes increased there. They would later become strict and people started looking for alternatives like OKX, MEXC, Bitget and Bingx at that time.

Certain exchanges just ask for ID and a video selfie while others will ask for your bank statement, what your job is, how much you earn per annum etc. Which exchange do you think the users will prefer?