They turned it around by not being GE anymore. The stock trading as "GE" now is just GE aircraft engines, aka "GE Aerospace". The healthcare stuff went to "GE Healthcare" (GEHC) and power systems went to "GE Vernova" (GEV)
GE finance was spun off into Ally bank.
The other part of the turnaround though was the pension. Pension funds in a zero interest rate environment is a giant liability. That was a huge part of what drag down GE's finances for a while. Once the interest rate started to go back up again, the pension liability shrunk by a lot.
Overall, GE is in a much better position now then it was in the past two decades. I don't know why the post ends up on such a negative note. GE has been severely humbled but I think it's well positioned to grow again.
I've invested in GE twice, both during its downturns. This time I'm holding onto it because I think it's structurally in a better place than it was before.