There's also the price discrimination angle of it. McDonald's has at least two sizeable groups of customers: people who frequently eat there, and are thus a change in the McDonald's pricing is significant in their total budget, and people who will occasionally eat there.
Presumably, some analyst at McDonald's found that the latter group wasn't particularly price sensitive, so they found a way to divide the two groups, and charge them different prices. The occasional McDonald's customer isn't going to jump through hoops, they just want to roll up, get their burger, and leave. The frequent customer is more likely to respond to changes in pricing in both directions. Having a system to actively prompt the frequent consumers to go more often, and then charge them a price that they are willing to pay, while still getting the full benefit of the people who don't really care how much food costs is a win-win from their perspective.
The surveillance is just a sweetener.
I fall squarely in the second camp, but what ended up happening was that I went from going occasionally, to not going at all.
McDonald's app-free pricing is now butting against actual sit-down restaurants, or a good local shop. I'm not price sensitive per se, but I don't want a raw deal, so I'll pick the better option. McD's used to be cheap and fast, now it's neither really.
Their sales are falling, and they're doing $5 deals now, so I'm definitely not the only one picking other options.
Yeah, they definitely got greedy with it. My go-to example is to point out the fact that In-N-Out used to be the fast food option for when you were willing to pay a few extra bucks to be served a better burger by someone who didn't look like they wanted to kill themselves. Now they're the cheapest option, by a substantial margin, and they didn't change a damn thing.