Why hasn't the cryptocurrency market experienced a widespread bull run in this cycle?

The main reason is the lack of new applications and models. In 2017, there was ICO; in 2020, there was DeFi; in 2021, there was GameFi. In this halving cycle, we only have Bitcoin ETFs and asset reserves, so the funds have flowed into BTC. Meanwhile, exchanges and project teams have taken advantage of people's desire to make quick money, wildly speculating on meme coins. The final result is that most people lose money, while a very small number of BTC investors make a profit.