Things have changed since your mums day.
Things to consider if you are worried about such things;
As everyone deals with labour and pain differently if external cues are used to measure how you are doing they can get it wrong. With ds they were shocked when after just arriving at hospital I told them he was about to fall out of me, so they looked and agreed I should push. 5 pushes and he was out. From looking at me they did not think I was minutes away from giving birth.
Things can change quickly, a friend gave birth in her bathroom because she was sent home.
Some monitoring can only be done via your fanjo, not just how many cms, but also for the baby. Also what if you need a catheter?
Even with hm and water births the mw needs to look so she can help you, it when to stop pushing, oh yeah and to catch the baby when it comes out.
Afterwards to possibly help the placenta come out.
After the birth to check re tears etc and possibly stitch you up.
Then is the rarely mentioned finger up bum with pain relief post stitching etc.
Afterwards your mw may want to check your stitches.
Finally if you have concerns re prolapse, looking and fingers will be required.
It's not a nice thought but you cannot have a baby and no-one ever look at your fanjo. Whilst to you it's your fanjo, to them it's just another one that day, and most of them have their own.