Anyone who says trump was worse should not be taken seriously about politics, all they care about is feeling good about their country and being able to ignore politics. Bush killed half a million Iraqis in service of oil company quarterly earnings, it's not even close.
I usually use half a million, as that's the undisputed number. I agree though that it's most likely a full million. Why would you believe anything trump says? And Trump's response to COVID is not nearly as bad as what bush did in Iraq.
If you want to compare them apples to apples as former presidents, W. Bush was easily worse. Trump on the other hand is running for president again, Bush is retired. He's happy on his ranch. Trump still has the opportunity to be worse than W. Bush. Comparing them like that is comparing apples to oranges, ones retired while the other is still active. If Trump is never elected again then Bush is worse.