This is great, if you have significant amounts of free oxygen to work with, which early earth evidently did not. Would be interesting to see if anaerobic metabolism could also occur without cellular confinement.
Biochemists have been doing just that for like 100 years. They'd take a bunch of yeast, grind the cells into a slurry releasing whatever is inside, separate the cell debris, and perform experiments measuring fermentation rate.
It can, that's the reason why UHT milk has a relatively short shelf lifespan and degrades despite being devoid of living microorganisms. The enzymes keep doing their work long after the cell membrane is gone.
Compared to other forms forms of liquid milk indeed, but it has a rather short shelf life compared to most sterile food. (Imagine if canned meat or fish had the same shelf life than UHT milk…)
Meat and fish subjected to the same processes as UHT milk (i.e., brief explosure to ultra-high temperatures) only lasts a few days, so UHT milk lasts way longer than the comparables.