She had a moderately successful tv show, which is only memorable because she came out as being homosexual a couple of seasons in.
Her biggest break was the Dory character in Finding Nemo, which was extremely popular, and got her an audience of children.
She got the daytime talk show, which was mostly fluff, but could be used to inject the correct narrative at the correct time. She created a persona of sweetness and light.
Lots of hearts, "Be Kind" as the motto, etc.
Biggest thing I remember was the "security guard" after the Vegas shooting, supposedly the hero, did one interview, then disappeared. It was a fluff interview on Ellen.
Recently, though, there has been a lot of chatter about the "frazzledrip" reference on her sweatshirt, the Epstein Island imagery on her set, etc.
So, suddenly, stories start popping up about Ellen being "mean" on the set. For over twenty years, you couldn't find a negative story about Ellen. Now, you can't find a positive one.
My conjecture: Ellen's usefulness is over. They're trying to find a way to memory hole her without referencing the darker elements, and couching it in a way that just says she was actually mean when she was pretending to be nice.