I understand that earnings in the present and earnings in the future might have different weightings.
How do you
know the earnings in the future? It's a guess, based on some data about the company and some hope about how the market will behave.
Value investing, which is the investment style of Buffett (and many others), looks at the intrinsic value of a company. This includes cash reserves, production assets, patents, debts to be collected, and a lot of other things. To simplify, if the company stopped selling products tomorrow, for how much could you sell it?
The advantage of this approach is that it is much more resistant to bubbles. The disadvantage is that it is much harder to find good opportunities.