You misunderstood. The ice cream products from
McDonald's all come from the same machine. I was not asserting they are the same machines at other fast food brands.
The fact that these machines are likely custom made, or partially customized just for McDonald's is even more reason why it's reasonable for McDonald's to force franchisees to use specific vendors for repair/parts.
Even with right to repair, McDonald's can force franchisees to use specific equipment and parts and vendors. That is their right as the brand owner.
Which means... there is no reality where joe-random repair company is going to be allowed to repair joe-random franchisee's machines using parts sourced from who knows where. It's just not going to ever happen, there's too much liability.
McDonald's wants a machine that's so brain-dead simple to use safely and keep sanitarily that even a new-hire with 5 minutes of training can operate it effectively. They get that by forcing standardization on one unit and one vendor, and software safety mechanisms that provide a firm no-go when something isn't right.
> And I'm pretty sure that people have done (informal) reliability studies by things like calling random franchises, and Mcdonalds isn't just more popular, it's actually less reliable.
You'll need some sort of source for this. Most fast food chains only sell one ice cream product, usually shakes or cones, maybe both. McDonald's sells McFlurries which are very popular, in addition to seasonal products and then the regular products. Given McDonald's is also the largest fast food chain in the world, it stands to reason they sell more ice cream products than anyone else.
Which would, yes, mean the surface area is larger and more exposed. People go there specifically for a McFlurry and come away dissapointed. How many people go to Taco Bell specifically for a milkshake and nothing else?