Realistically, I'm only changing strings every few months. Like maybe six months. A job I hate to do but love the result, As long as it keeps sounding good when I pull it out of the case, I leave it alone,
This is a pretty common thing it seems.I don't care for the bright sound of new strings or the need to stretch and tune (rinse and repeat). I acquired depression era habits somewhere along the way and will use something til it breaks. I've gotten multiple years out of a set of strings with near daily play.
At some point, tuning becomes an issue again and I change strings.
I would love to see the data surrounding sound degradation over the life of a string.
D'Addario J16 Phos/Bronz/Light
Onlky when one of the strings break, then I change them all. Years, at times.