If there is a finite limit of "investable assets", then the relationship between those assets prices is not necessarily driven solely by sentiment in favor of Apple.
It could be that almost all other assets have seen their expected future cash flows fall while Apple's has slightly risen.
It could be that people's decision is not driven by future cash flows, but some other metric or feeling.
Have Tesla's expected future cash flows increased by 8.6X in the past 12 months? It's stock has gone from $220/share to $1,900/share.