I'm chronically ill too Stavros and am childfree at 43. I've had a bilateral salpingectomy through clinical need but I'd decided not to have DC long before that.
Firstly, I'm ill. How on earth can I expect to take care of children when I sometimes need people to take care of me? Secondly, I do feel as though some people have them because 'it's what you do'. Interestingly, your OP does not mention you actually wanting them - just that your friends have them and you feel left out.
There is nothing missing from my (pre-covid) life at all - quite the opposite really. It was full of books, films, travel, friends, family, music, politics, art galleries and museums, courses, sport, work, lunches out, plants and gardening and a lot more. Oh yeah, rheumatology appointments too!
When I was doing my A levels and my degree, I worked as a care assistant to make ends meet. Sadly, most of the residents I looked after had no visitors, despite having had DC. The residents who did have visitors were visited by friends, the vicar/rabbi, ex foster children, old colleagues. People who were there because they wanted to be, not because they were obligated.