Children vary and different stages suit different children/ parents.
My two were rougher than average on the night feeds as infants, following on seamlessly from drainining pregnancies and tough births. They were content babies in the daytime though. I remember waking up each morning feeling like I had a stonking hangover from the physical tiredness. I used to wish it was a hangover, because then I'd have enjoyed earning it!
A decade on, I'm a decade older. I get the sleep, but the mental load is much higher having to support two high functioning ND children with executive function issues, at two different schools. For some things like getting ready in the morning, I still have to stand over them like little children to complete routines like brushing teeth. What I do miss from younger years, is adult time. Their waking hours are similar to mine. I haven't been out with DH as a couple in nearly 4 years- first the pandemic restrictions, but a lack of babysitters as those who babysat years ago have moved on in their lives. With an autistic 12yo, he's not quite old enough to leave for a night out (fails the tabloid headlines test), particularly with a younger sibling, but having an unknown person in the house with him would be worse for his happiness level. Already, things like friendship issues are harder to resolve and work around. My evenings aren't spent with the CBeebies bedtime hour, and baths, they're driving around Cubs/ Scouts etc... then dinner... then reading. When they're in bed, I'm in bed.
5-9 tends to be a sweet spot in the middle.
I haven't forgotten the toddler years. If I see a cute baby that makes my ovaries twitch, muttering the word "toddlers" until the feeling passes is very effective.
Parents of older children/ teenagers have been there. The challenges change and some children suit different ages better, and the same for the parents. I bear in mind as DS gradually mutates into a teenager that at least he'll have more speech than he did as a toddler, although we are regressing into grunts and Kevin the Teenager-esque tirades. The trouble is, he's now too big to scoop up under my arm like a rugby ball and anchor him into a buggy/ car deat and get things done.
The other many challenge many families face with time is also aging grandparents and becoming the squeezed generation between older children and grandparents both needing support with their independence. Add in that that tends to co-incide with the menopause and you can have a tripple whammy.