All the scientists looking for life already know this. But we also know how far away the things we're looking at are, and therefore how far in the past we're seeing them. All the planets we look at are within our own galaxy, and we only see them a few tens, hundreds or at most thousands of years in the past, definitely not at the beginning of the universe. Even looking at the opposite side of our galaxy would only be 100,000 years in the past. And even other galaxies are millions or tens of millions of light years way, which isn't anywhere close to the beginning of the universe.

It's only observations of ultra distant galaxies that are billions of light years away that are seeing significantly nearer to the beginning of the universe, and we're not looking for life in those observations.