The easiest way to interpret this is that the market cap size is what investors expect the market share to be in about 2,3 years. That is that Intel would have about 70% share compared to something like 90% today.

PE or net income is not really relevant for AMD as they are in very high growth phase (and because their gross margins are fine). The most important thing here is that Intel is failing to execute on the upcoming fab process which will unequivocally make them less competitive from 2021 - 2023 (at the very least). The uncertainty of Intel being able to execute here on out is also impacting their share price since they have had a long history of failing to execute on 10nm and now on 7nm.