To be honest I can see it from both points of view. There is 4 years between my 2 children.
I found it a lot harder to cope when my eldest was a newborn. To go from having none to 1 was a nightmare for me. I was unprepared for the utter tiredness of having broken nights sleep.
I was also terrified I was doing everything wrong. Did I make the feeds right? Is she feeding enough?sleeping enough? Breathing properly?
Worried when she was eating solids that she was not having enough. She has always been slim and long with a small appetite.
And bathing was scary! What if I dropped her? etc
Used to take her to the doctors at sign of illness even just a cold as was terrified I would get it wrong and it would be serious.
I spent a lot of one on one time with her. We would do lots of baking, arts and crafts, playing with her toys.
She was at preschool 3 hours a day when my youngest was born so used to do all my shopping/cleaning in that time so when she was home all attention was on her.
Days out were easy as just catered for her needs.
Routine was easier though she was older when I needed to get her into one as did not really have anywhere we had to be at a certain time until she went to preschool.
Youngest came along. I was a lot more calmer. Did not panic the same over feeding, steralising, bathing, eating etc.
As we had her older sister the little one just had to slot in with our routine.
Found it OK to do preschool runs. She spent a lot more time in sleepsuits rather than outfits like her older sister did as it was easier.
Days out are harder as we have to try and cater for a nearly 6 year old and a 20 month old. Especially difficult now the youngest is walking as she wants to go places to have a run around.
I do not spend the same amount of time with my eldest as toddler is always around so that is tough. But also youngest does not get the same amount of time and attention like my eldest did. She is very content to play on her own most times while I get housework done etc.
So to be honest for me there have been harder/easier things from both angles.
I do agree you are more confident and relaxed when 2nd, 3rd, 4th etc comes along. You tend to just do what needs doing instead of getting a bit obsessed with it all.