My experience is second-hand as a child and teenager while my father was working there, but I've talked to him a lot over the years about Welch and things like stack ranking, six sigma, etc, and what the company was like in the 1970s before Jack took over.

The short version is that GE was an inefficient bureaucratic and operational mess at all levels - as I said, all the way down the shop floor. Welch came in and almost instantly turned the culture around - again, at all levels - and made it one of largest, most improved and respected companies ever.

This article [0] from 1986 sums it up better than I can, but it rings true. They truly were boom times for anyone employed at GE - yes, if you survived all of the (necessary) layoffs.

A note about stack ranking, since everyone complains about it:

C players were not just summarily fired - they almost always had a few quarters to either improve, or move to a new team. It's not as ruthless as people make it out to be. An employee had to consistently underperform to be fired, although it's true that they didn't get very many second chances.

[0] https://money.cnn.com/magazines/fortune/fortune_archive/1986...