Why is the bottom formed through grinding rather than smashing?

Because grinding has much more destructive power than smashing.
Some people objectively cannot withstand the grind,
and for various reasons, they passively surrender and give up.
Most people cannot handle the mental stress of grinding.
They think that capital has a time cost,
and instead of grinding in one place,
it's better to invest in more effective fields.
So, after a long period of grinding,
these types of funds will continue to flow out.
Only by grinding out both types of funds above
can the bottom be considered truly healthy.