Having finally looked up the numbers on the Iraq war, yeah, Bush's presidency is numerically worse than Trump's so far, esp. when you add in all of the domino effects. That being said, I think Trump is still worse person morality wise, has done more to damage his own country than Bush, and is constantly consorting with (other) authoritarian governments to do crimes. Check out Seth Abramson if you haven't already; he's been compiling all the crap we already know Trump's done.
yes I think it’s difficult to compare {Bush, Obama, Trump} because we inevitably conflate the personal character of the man, the overall executive team, the things that they did, the things that they tried but failed to do, the things that happened during their term, and the norms that they established for their successors, all of which are important but in different ways.
Trump may be the most repellent character of the three, and he has done some bad things, but he has also failed to do a lot of things -- like repealing the ACA -- and many of the bad things he has done -- like increasing the frequency of drone attacks -- were built on norms established by the Bush administration and reinforced by Obama.
it gets even murkier if we ask how much responsibility the Democrats have for the Iraq war, given that many of them supported it, or their opposition was patchy and conflicted, and they made no serious effort to rollback the Bush doctrine afterwards.
it raises the question of whether further American aggression in the Middle East was already determined regardless, just as intensifying the Cold War with China appears to be settled policy independently of Trump and will likely continue in a bipartisan manner after his departure.
nevertheless you have to begin somewhere, and blaming the guy who pulled the trigger is a sensible starting point before moving on to the structural forces that put the gun in his hand in the first place.
