I've found the difference in runtime between similarly-priced low-end units with similar power rating is hour+ (LifePO4 power station) vs not advertised but actually just minutes (lead acid UPS). And you can spend a bit more on the LifePO4 power station and get a proportional increase in runtime and power, vs. the lead acid UPS where the cost would quickly become prohibitive. And the LifePO4 power station gives you the choice to cut off above 0% or not, where the lead acid unit doesn't give you any control. So you can trade off 30% of your capacity for increased longevity if you choose and still come out way way ahead on runtime. Or you can not and still have much better battery longevity than lead acid. You can choose a spot on a Pareto frontier that lead acid can't even approach.

The rationale I've heard to justify conventional UPSs not even trying to compete on runtime is that they're just for giving you a few minutes to cleanly shut down your crap software that isn't crash-safe and/or for your auto-start generator to start up. But what I actually want is to keep working for an hour+ after the power goes out without owning/installing/maintaining a generator.