People are motivated by different things. "Below market" only matters if you judge yourself by how much you're paid compared to your peers. "Having no work-life balance" assumes that your "life" doesn't benefit from "work" in ways other than the size of your paycheck.

If you already have a house/apartment you like and will still be able to afford with this job, find the work you're doing interesting, have the appreciation of your co-workers and the freedom to do your work the way you want (because no one else who works there is an IT person); if you find playing video games with colleagues a reasonable facsimile of "life"; if being a visible member of a team that has a youtube channel with 10s of thousands of subscribers who look up to them is more important than owning a bigger TV; then this job may be worthwhile for you.

And why is it a problem that someone would rather have those things than a salary at market rates, or an ability to go home at 5pm and spend time with their family not thinking about work?