I cannot speak to the TEC case. I haven’t attended, save for one wedding and one funeral, in 50 years.
In my Continuum parish, heavily Anglo-Catholic, attendance is around 50 per Sunday Mass, total parish membership maybe twice that+. Age is indeed on the gray side. Until a recent influx of main-line protestants, seeking refuge and liturgical , orthodox worship.
We do out-reach as we can, including a permanent Anglican chapel just off the local university campus, with good student interaction, and folks from there drifting into the parish.
The situation is more favorable than it was (IMO) 5+ years, but we are not prospering as well as one would wish. But then, no true Anglican would be an optimist.