What shocked me when I first dealt with ILLs was how few contingencies seemed to be in place in the event of anything going awry.
I had one visit in 2022 where my friend and I bought an ILL for an advertised time that worked for us...only to realize that after our payment went through that the time had changed, and now we were scheduled to ride during our dinner at Napa Rose.
We went immediately to nearest the Guest Service kiosk...and they basically told us they couldn't change anything. The only thing they were able to do was to refund the original purchase, and then we could re-purchase it, hopefully resulting in a better time. That was their solution! As if it had never occured to Disney that there might be some sort of justifiable reason that people couldn't make their prescribed time, or that their system that they forced everyone to use might possibly create sub-optimal experiences for some guests, or indeed work against existing plans they had made. No changes can be made, even as a result of pre-existing plans to drop a lot of money into Disney's lap that they would ostensibly want to encourage.
This was the same trip where I couldn't cancel an accidentally duplicated dining reservation the night before through the app OR at Guest Services (apparently they were powerless to do anything once the restaurant had closed for the day?) OR through their dining hotline, which automatically hung up on me. I literally had to go into the park the next day, far earlier than I had planned, and go to the actual restaurant host stand to cancel it...and even then it didn't show as cancelled in the app until it was officially lunch time in Disney's system. They've made it way easier to cancel in the app until it's almost mealtime, which is a good fix, but there's still more that needs to be done to meet the level of service they claim to be offering.
Sometimes I think people are too harsh on the modern parks experience, but then I remember some of the nonsense I dealt with in 2022 (or before...there was an awful experience with WDW in 2018 in line for Big Thunder, which involved a flood of FP+ users, a crawling standby, the clock ticking on a dining reservation, and mishaps with their dining hotline) and come to the conclusion that there are definitely times I'm not harsh enough.