You are basing this on a meaningless, hypothetical head to head poll on a contest that hasn’t even started. I don’t think any reputable pollster would assign any statistical significance to those polls. Reagan trailed Carter by ~30 points in March 1980. Was there any statistical significance to those polls? Should Reagan have dropped out in March because he was about to get landslided by Carter?
I realize that the polls are not terribly meaningful at this point. But Trump does have a ceiling with the voting public and we really don’t know yet where that ceiling is. The polling is all we have right now and it does not look great.