Either out of choice or necessity due to lack of hair dresser opportunities/ hair dye if you DIY.
I've debated just growing out the dye for ages, particularly as I have a few friends who have and look good. All mid-late 40s. But I've worried about the usual - looking scruffy, being judged etc.
Last time I had a few streaks put in (last summer) it took a lot more than I expected and instead of a few lighter bits in my light brown hair, it left me blonde with some mousy brown/red lowlights left where the streaks took less. Quite the surprise at the time, but it got lots of compliments. So I left it and didn't dye it any darker. Instead, it's left me putting a light blonde on occasionally just to blend in the grey roots and to 'smudge' the growing out line.
It was (over)due doing when the lockdown started, so I have about 2 inches of grey merging into a blonde. I do have another bronde highlights kit if things got too blocky, with the view to lighten the stuff that still grows through on the underneath layers darker than the rest, but I'm holding off as long as I can bear to see what it will look like.
I'm actually interested to see how it will come out if I keep growing it out. I'm very white/blonde in the grey at the temples to more of a salt and pepper grey at the back and underneath.