I watched the Netflix tribute special today. More nostalgic than hilarious, but good to see some of the clips again. The new stuff should have been zanier and more rambunctious. Just using profanity doesn't make it hip or hilarious, and the sense of madcap abandon was completely missing.
She was top-billed in the Broadway revival of The Boy Friend in 1970, and I suspect that's why she left. The show only ran four months or so, but I suspect after it ended, she didn't want to go back to old triumphs and looked for new challenges. Sadly, she didn't find them.