If you were referring to the Russia investigation, there was no predicate to start the investigation.
The predicate was when a Trump campaign advisor told an Australian diplomat that Russia had politically damaging material on Clinton.
I don’t think this is sufficient to open an investigation. The amount of lies told at bars is off the charts. If everything said at a bar were to be believed, investigations into everyone and their brother would be opened, and everyone would have a Nobel peace prize (not the participation kind that your side advocates for).
There are not any Chinese companies that need saving. They are all state sponsored entities whose purpose is to benefit the CCP and steal IP/technology from the West.
Trump also already made a fortune as a private citizen, he didn’t need to become president to get rich. Biden on the other hand left public service with multiple mansions after spending his career on a ~120k/year salary; a good salary but probably not enough to pay for the kind of lifestyle he is living.