OP I had a 3rd degree tear on my first and no continence issues at first, but in the physio check I had to follow up on the tear (which I wouldn't have had) they basically said my pelvic floor was shot to hell and if I didn't start work on it now I would end up with serious continence issues.
After a long time with that team, I have come to the conclusion that most of the issues were pregnancy-related and probably wouldn't have been picked up till I was menopausal. Apparently its v common for continence issues caused by pregnancy not to turn up till the menopause, esp in women who haven't breastfed, to do with oestrogen levels. So... its possible lots of women who had section will have subsequent issues, with a delay.
I have a total choice of a section, obviously didn't have an ideal first birth, but don't recognise what your'e describing. I know lots of women who tore, and some who had surgery, and all are now pretty much fully recovered. I also know women with nerve damage and patches of numbness from sections that will never go, who had repeat infections, and personally what is putting me off the most is the recovery time.
So... really I think most of the issue are down to inadequate postnatal support. I had the textbook nightmare birth: induction, intervention, episiotomy, tore through episiotomy. (Thankfully also an epidural thrown in late in the day) I still found it ok, and would have chosen it over a 'standard' c-section because I was so quickly back to normal.