Because there’s been a decline in experience across so many fast food and fast casual restaurants over the last ten years, regardless of when they were founded, it seems like something industry wide (maybe data is part of that) rather than a business cycle.
On the other hand, fast food places around me have large digital touch-screen kiosks for ordering. You can always go up to the counter to order, but it seems like everyone prefers the kiosk if one is available. For good reasons too -- you get to see what the food looks like, you don't feel rushed, etc.
I'm not so sure the experience (of talking to fast food employees?), if you can call it that, matters all that much to people who want to grab a quick bite with their family.
To me the biggest change in restaurants is the norms/expectations of service personnel. e.g. I'll walk into a restaurant and the young hostess might stare at me until I go "Uh, for two please". Or the waiter at a restaurant might make it feel like he's only standing in for his friend and never was a waiter before in his life before I release him back to the waiter social circle going on in the corner. But I can't blame that on "data".