Ok, I have been to WDW many times over the last 3 decades, and DL just 1.5years ago (2019 between XMAS and New Years). Not once in my adult memory (last 15 years) have I waited in any WDW line for more than 45-50 minutes, and we did FOP without FP within 2 weeks of it opening.
Yes, every time I go I take the time to formulate a detailed touring plan, but it has worked every time. I know not everyone wants to do military level planning for their vacation, and that is fine. However, the tradeoff is waiting in line for 2-3 hours. It really isn't required though, with or without fastpasses. You just have to be smart about how you do it. When we went to DL during the busiest week of the year, we rode every major ride within 30 minutes or less multiple times. Outside of FOP, wich was about 45-50 minutes, we haven't waited for a ride without a FP for more than 45 minutes ever. The trade off is that I have to plan out a detailed plan of what rides we will ride when, and stick to it. However, I don't mind that planning (type A analyst). I do all the planning with my family's inputs. They get the joy of not waiting and no planning, and I get to stay in control.
Like I said, not everyone wants to do that. However, they realize there is an opportunity cost. Gone are the days when you can stroll into that park the day of with no planning, do whatever whenever, and not care. If that is how you want to play it, fine. However, there are more people on the planet now than 50 years ago. Gone are the days when crowd control at the parks was not an issue. Lots of people, with no planning, equals long lines.