Regarding stickers on PCs, once one PC manufacturer added a sticker for feature X, they would have an advantage in physical stores over the other manufacturer’s PC next to it, because consumers overwhelmed by the available choices would rather buy the PC with the indicated feature over the one that might not have it. If Macs were available from different manufacturers and displayed in stores side by side, I’m not sure that Apple could escape that mechanism.
Is "Intel inside" even a feature? It's not like the other laptop will be lacking a CPU.
You can read up the history here: https://en.wikipedia.org/wiki/Intel#Intel_Inside. Nowadays the considerations aren’t exactly the same anymore as 20-30 years ago, but by some measure Intel CPUs are still the most interoperable x86 CPUs, due to their market share.
I'm not sure this explains anything? It is the story of one successful marketing campaign in the 90s. Intel's reputation in the 2020s is not what it was then.