Imagine caring for someone who is sick and no money is exchanged. This activity is measured as having no value by GDP.
Imagine raising a child without being paid for it. This activity is measured as having no economic value by GDP.
Imagine charging for the care of people who can't care for themselves. Imagine minimizing your costs to the point where the number of people who keep up with the hygiene of those that can't for themselves is so few that on average the aides hired have only 20 minutes a day to take care of each person's needs including washing, dressing, cleaning teeth, cleaning asses, etc. This is valued highly when measured by GDP.