CS PhDs are different than biology PhDs. They are still low-paid relative to industry, stressful, and competitive. However, multiple postdocs in CS are pretty u

CS PhDs are different than biology PhDs. They are still low-paid relative to industry, stressful, and competitive. However, multiple postdocs in CS are pretty uncommon, and it is not uncommon for a PhD candidate to get faculty offers with no postdoc (though many do a year of postdocing anyway, since it's less pressure than being junior faculty but at least twice the pay of being a grad student). I think a reasonable rule of thumb is that the quality of life for grad school in area X is directly proportional to the employability of a BA/BS or MS in area X. In CS most anybody doing a PhD at a decent school could leave for a CS job paying at least twice as much. In biology this is less true, and in the humanities it's even less true. IMO this explains mych of the difference in grad student experiences across these areas.