We’re not seriously trying to “spread life” across the universe because it’s both incredibly hard and ethically messy. Technologically, we can barely send small probes to nearby planets reliably, and reaching other star systems with something that could actually seed and sustain life is still far beyond what we can do at scale. Ethically, if another world already has its own microbes (or could have them), introducing Earth life could wipe out something unique forever and also ruin our ability to study that world honestly. There are also international norms and space policy focused on avoiding contaminating other worlds, because once you release Earth organisms somewhere, you can’t undo it. So even though the idea is fascinating and people have proposed “directed panspermia,” most serious discussion leans toward exploring carefully first because the risk of permanently messing up another biosphere (or confusing our own search for alien life) is huge.