I'm well aware of the Intel history, doesn't mean Apple suddenly can beat Qualcomm
I don't think Apple cares about "beating" Qualcomm tbh. They care more about being independent of Qualcomm. Before the C1, Qualcomm had control of hundreds of billions of dollars of Apple's valuation depending on whether they decided to continue to sell Apple modems.
IMHO most consumers think the 5G roll-out was just an excuse for carriers to charge more money and push expensive phone sales - and it is somewhat true in that 5G is more about telco architecture and efficiency. A 5G tower can support significantly more service to more customers than a set of LTE/3G/Edge towers. The 5G architecture is meant to support a suite of new connectivity options that carriers can sell that were infeasible before. And a 5G capable phone can potentially use a lot less resources on the network than older phones will.
So 5G on its own isn't really a differentiator more than a qualifier - people would be worried about a non-5G phone becoming obsolete too soon, and carriers would object to new non-5G models being sold for their network.
In terms of actual differentiators - I don't think even a sizeable minority of people are going to buy a phone because someone told them it has a higher peak data transfer rate over cellular networks - they care more features like all-day battery life and the ability to place calls in low signal. People want their data to never be slow (stalling, sub-ISDN speeds) more, because they can't really internally qualitatively evaluate a claim of "fast".
Apple also has an advantage advertising differentiating features because they are picking the features they want to develop themselves. Qualcomm can have advanced LTE features like predictive tower seeking, but it doesn't do much good if the phone platform ignores it, and doesn't make Qualcomm look any better if the OEM doesn't advertise it as a feature. Apple can plan out features to pitch as a coherent package justifying new phone model upgrades.
Qualcomm also has a disadvantage that they announce a chipset months in advance of release, and then may have months more delay until flagship products ship with it. Apple presumably will announce any new features in the C2 in a two week window of delivery to consumers.
Qualcomm's biggest disadvantages though in differentiating their product is that they are really only capable of doing it to their customers - phone OEMs. Android handset manufacturers aren't picking between an X80 and a C2. This is a challenge Intel has faced as Apple moved away from x86 processors - Intel can't do anything directly marketing-wise to prevent people picking a MacBook Pro over a Lenovo.