IMO:
From all the comments by their friends it appears that since Covid hit BA kept HG isolated in their home.
That's quite a few years and we don't know if during those years GH or BA were under the care of a doctor, even just yearly check-ups.
A hermit existence can be very unhealthy and leading to neglecting oneself and their surroundings.
All their friends spin their relationship as 2 love birds hiding away in their love nest as mama bird protects papa bird when the reality could be the complete opposite.
Social isolation can cause havoc/deteriorating one's mind and habits.