We take the whole family to a four-generation, ~20 person in one large house lake vacation a week in the summer. With enough people, you get some downtime (and some doubled-up-upon time).
We really like the winter week away, but the summer vacation with the large family is more fun and differently semi-relaxing.
Things also get easier and more interesting as they become self-cleaning, self-loading, and self-entertaining (when they can read). Until age 5 and especially 3 and younger is intense. It lightens up some.
Your life as a parent needs to be only partially about your kids. You need to keep and nurture your adult relationship as well. It’s not ALL about the kids.
We also make it a point to split housework and give each other “time off” to do hobbies, go to the gym, go out with friends, play sports, etc while the other adult has the kids. Keep a shared Google calendar to coordinate things.
It’s a series of small things, integrated over a long time.
Unfortunately, I think most of this is far from real for most parents.
The greater point is to structure your life and relationship so as to have an escape valve that lets you keep your individual and adult couple identities/interests and not merely become 100% pure parent for a decade straight without break.
I have a 2 year 3 month old - she is the joy of my life and makes me want to live, do well, be a better person for her. Over the last couple of weeks she has started waiting for me to come back from work by waiting near the window. When I leave for work, she gives me a hug and then runs over to window to wave goodbye. I can say this with utmost certainty that no one has give me such an unconditional love like she does. I love her more than life itself, would not hesitate to go to extreme measures with a happy smile on my face. However every now and then I think of times before her and sometimes wish we (my wife and I) can be spontaneous - take a weekend trip to portland with zero preparations, or careless - sleep in until 10am and watch the office reruns, supercut of all godfather movies. You find more relaxing things to do though.
Here is a parenting trick:
Last year on our trip to Hawai'i, we had a room near pool, once our daughter was down for a nap, we'd walk out of the room (with do-not-disturb sign on door knob), with a baby monitor pointed directly at her crib, walk 20 feet to the pool bar, order drinks and hangout and watch her sleep on the monitor. I turned it into a game, order every beer that bar offered (not quantity, variety). That was the best vacation so far.
Looking forward to describing this to the Booking Agent:"We need a room, close to the bar & pool. And a kids bed please."
To be honest, I can't wait to get back to work after a vacation so I can finally find some relaxation time. Vacations with kids is exhausting. Going to work is like a true vacation after going on a vacation with kids.
If you want a relaxing vacation, you have to ditch the kids. On a regular basis (1-2 times a year) my wife and I have the grandparents take over kid duty while we get away for a few days. This does take some scheduling since our parents do not live in the same state we do.