I saw an interesting news article on bonkers names a while back (a spin off from the girl called Blaer in Iceland who had been seeking recognition of her name as a girls' name). What the commentator was saying is that, in countries like the UK and US we are aghast at the idea that someone could have a say in what we call our child. The attitude is "this is my child. Naming is my right. I can do what I like. If I want to call my child MoonUnit Dweezil, I can" This was contrasted with other countries, like Germany and Iceland, where naming was seen as something which the state had a right in in the best interests of the child.
I can see parallels in this situation here. In the sense of balancing rights over our children and responsibilities towards them (not that I'm suggesting the state gets involved in park trips. The analogy doesn't stretch that far!!).
The OP is is saying. This is my child. I want to be there for everything. That is fine, if the person being impacted is just her. If she is negotiating days off every time nursery goes on a trip, etc.
But if it becomes about the needs and wants of a parent. If it means a child's relationship with grandparents being impacted because they never get to do anything fun and new together. If the child is missing out on birthday parties because the parents want to be the first ones to take them to X, well then it's about being selfish. It's about seeing a child as our right.
OP, it is interesting that you have talked about these things from the perspective of things being taken from you. Now, I'll give you the benefit of the doubt and assume that your baby is still young and hasn't really developed an identity separate from you in your mind yet. But pretty quickly, children because people in their own right. And it should become about what is best for them, not what we want as parents. If DD1 had the opportunity to go to the zoo with my parents (actually, she's been before, but let's assume she hadn't), then at nearly four, I would be thinking "how lovely for her. How lovely for her to do something so exciting with my parents", not "you are taking something from me". It's not mine to give, or theirs to take. It's DD1's opportunity. Doing new and exciting things together is a lovely way for them to build shared memories and enjoy their own relationship independent from me.
Finally, yes, I have heard people regret missing so much of a child's childhood, often because they were working such long hours. But I've never heard someone, with the benefit of years of perspective, complain that they missed x, y, and z minor firsts. Missing things like first steps are sometimes referenced, but generally as being symbolic of something wider. More often people talk about missing time, missing getting to know their child, shared memories. Those don't have to be firsts. It's not a list of achievements.