If the obscenely wealthy benefit most from having Republicans in power; and collectively they have disproportionate control over the economy; wouldn't they use that power to sabotage Democrats?
I think that's only a consensus among people who don't understand the economy very well. The truth is politicians have very little control over the economy particularly in the short term. At most politics is able to nudge the economy very slightly like the rudder on a massive ship that takes years to turn.
Course there are some things you can do. Tariffs is an obvious one, completely bungling a global pandemic is probably another, etc..
It's pretty difficult to control a lot of the economy still, especially where international concerns like the OPEC price setting cartel, yet oil prices are often blamed on leadership.
...but also, establishment politicians have a pretty fixed economic ideology that doesn't change all that much, further constraining their reactions which are mostly classist.
Then there's macroeconomic policies like interest rates, which globally Western governments seem to prefer to leave entirely up to central bankers.