There is no bad or good time to get in day trading, you have to know first if you have the skills to be consistent, so you will end up profitable.
Crypto market has a lot of coins trading, not only BTC and the volatility is still high, so if you have a working strategy, you don't need to wait for the bull market to trade. If you look at the trading volume here
https://coinmarketcap.com/charts/ in general, there's a good volume on a daily basis, which means people are day trading ever since.
I agree, no single time is good or bad for everyone in day trading. Markets keep moving and ones success depends on how one handles the situation.