If the halving is a known event, why do people think it’s leads to price increases?

So I love and stack Bitcoin monthly and have for years.

However 2 things I’ve come to realise don’t make 100% sense to me.

1) the halving is a known mathematical event so how is the supply reduction not already factored in to price?

2) the finite supply is a massive talking point for Bitcoin (and I love this fact) but what makes it different from a company that has a certain amount of shares? I know companies could do a stock split, but say for Berkshire Hathaway if they don’t issue more shares and people have to fight over the current share volume why doesn’t their price go totally parabolic like many YouTubers say Bitcoin price has to because of a “supply crunch”.

Genuinely curious to find out what people think about those two questions.