I’m not sure this is universally true, but in most contexts I’ve heard while studying Japanese and visiting Japan, サラリマン (sarariman) indicates someone with the kind of lifetime-employment, “I live in town in a coffin hotel during the week and only see my family on the weekends” job that used to be common for white-collar workers.

The identity, uniform, and work ethic are all part of the package. It’s been a while since most big companies in the US could claim that kind of life-long career and mutual loyalty was likely or even desirable, but early IBM might be an apt comparison., down to the dress code, company songbook, and 40-year tenures for senior staff.