Well, let's say in 10 years Bitcoin is widely used worldwide.
What would the fee be for a cup of coffee? Because if it's too high no one will use it for such payments which is a shame. Of course, that's where LN would solve things to make it cheaper, but it's not "inside the chain". It doesn't feel like "real Bitcoin" or something. But I also don't see any other solutions for this problem. Centralized nodes is a worst case scenario.