Well, OP, you're almost there. Just dont have another kid

For us, once out of diapers, strollers, it got much easier, since you need less stuff. We also shaped trips to our kids capacities--did a lot of fairly chill beach and family trips when they were little and made sure we built in lots of down time when we went to places like NYC, Paris, etc--one or two things a day was good, rather than packing it all in.
Our experience was also dependent on the child. DS was highly mobile and had trouble changing routines as a baby/toddler but once screens were on the table (age 4) he was fine on any long flight. DD was a pretty easy baby and toddler (she often just slept on planes, cars, anything moving) for hours, but developed a shyness and stubborness around 4 and was far less interested once we got to a place and wanted her routine. They are still kind of like that at 10 and 12 in certain ways--DD is less adventurous and misses her friends, her room, the dog, her pillows, etc, while DS gets into new experiences quickly.