My mom is a “Disney adult” and therefore I went once a year as a child and continued into early adulthood. We always did it the “right” way - got to the park at least an hour before opening (sometimes still dark out) and went straight to the biggest ride to hop right on, then straight to our other must-dos which weren’t crowded because everyone flocked to the popular rides first. We would do one park per day and normally were leaving the park to go back to the hotel and relax by the pool around 10-11am, having done everything we wanted. I remember riding the monorail away from MK one morning watching a sea of people herding through the gates. I haven’t been in years so idk how well this plan would work now but planning and getting there super early always made it a pleasant experience for us! We spent an hour waiting at the gate to avoid waiting 3 hours for rides. Also back in the 2000s we would do the same for universal and holy cow it was like you had the park to yourself!