I understand the falling knife thing for individual stocks, especially when it doesn't follow the market as a whole. But as far as diversified ETFs go? Nobody can time the market. Statistically speaking, there's a lot more money to be lost by waiting than there is to be made by timing the market. DCAing is key.
Tons of people were waiting for a crash back in 2019. Or 2018. Or 2017. And tons of people were waiting at the bottom of the 2020 markets. It was surely going to keep declining. It was so obvious. Yet it didn't and we had a very, very quick recovery. I remember that vividly. I'm not saying this will happen again this time though, just that you can't be sure. Most people don't know they're the bottom when they live through it, just the same way they don't know they're at the top.
I'm not saying you're wrong, by the way. Things might get worse and I wouldn't be surprised in the slightest. But since nobody can't know for sure, the best way is to keep investing regularly if you don't need the money before 10+ years. Of course, you could be right this time and things get significantly worse and by waiting you'll improve your gains. But will you be able to guess right the next time? And the one after that? Unless you're one in a millions, sadly, you won't. That's why DCAing is the best way to go unless you're a professional.
Anyway, I'm just a stranger on the internet so don't make financial decisions based on my advice. But reading on the subject (which you might already have done and decided its not for you, which is fine) might give you another perspective.