Not really — your tone is too sarcastic and know-it-all but okay, I’ll answer anyway.
Trump didn’t kill all 500,000+. But it’s been suggested at least half of the deaths could have been averted with better leadership. So, he’s responsible potentially for up to 250,000+ Potentially
Things Trump could have done: 1. Don’t publicly contradict your own coronavirus expert health advisor thereby undermining public knowledge of best practices and undermine efforts to change the deep-seated belief among many (esp. Republicans) that Covid wasn’t a serious threat. 2. Come out early and strong in favor of masks, distancing, etc., again to reinforce the effectiveness of those methods at reducing transmission. 3. Don’t back the wrong horses (HXQ, plasma therapy, sunlight & cleaner “treatments,” etc.) that turn out to be flops, giving people false hope and again distracting them from what actually has been proven to work.
This isn’t rocket science. The virus spreads through the air esp. in tight quarters. Follow doctor’s advice to limit those events. So do everything you can to discourage casual virus transmission.