Still tricky to say “the evidence”. It’s unscientific to look at physical material and backstory it into being “evidence”. Nobody was around to observe Toba either.
I didn’t witness my own birth either, but I’m 99.99% sure it happened.
It’s hard to know where to begin. There is nothing whatsoever “tricky” about looking at the natural world and finding evidence in its “physical material”. That evidence can tell us much not only about its present state, but also about the past.
As for Toba, there were plenty of people around to see the eruption, but no one nearby survived, and even if some had, they would all be dead by now, so their evidence would be discounted by you. The notion that the world came into existence at the moment of your birth is solipsistic and not the least bit scientific.
I think you are more than a little bit silly.