The issue is that almost all the factors you mentioned- quality of work, work-life balance, chance of advancement, company culture... - are all aspects you can only have the vaguest of ideas about before you start in a new company. And a mistaken evaluation of even a single one of them can change completely the score of the offer.
Not 100% true. It depends on the industry, but I have a pretty good idea of the good and bad of many of our competitors. You're right that some of those factors are fuzzy.
