But yet, the market always react to the 4 years Bitcoin miner's reward halving which is one of its utility: a feature that makes it a store of value by creating scarcity.
Upturns in the price of BTC occurred a few times in a roughly coincidental way with Bitcoin's price. Insofar as you call it a pattern (like those stars the Greeks said was a guy in a horse shooting a bow and arrow), it's a pattern that has no reason to follow next time. (Of course the "pattern at all costs" people will just make up some new pattern the price supposedly follows).
And in any case, the alleged "halving pattern" wouldn't explain why Bitcoin is particularly at any actual level like $150k or $1.50.
It won't, the incentives won't be worth it for miners, and we all know miners are very important to the network.
The mining difficulty adjusts, so Bitcoin would not stop working if the price went down.
So all the onchain transactions are done by robots? Or possibly AI's?

Can you explain what you meant by this?
If Bitcoin was just a worthless project or just one of those payment services back then in 2008, how many users and investors would it have today? Well this is just a hypothetical question because we can't tell for sure. But what I'm trying to say is that Bitcoin's utility attracted investors, contributors, miners, node runners and all sorts of users to it, not just the name "Bitcoin".
I'll answer your theoretical with another theoretical: if Bitcoin was fixed in price like a stablecoin, would it have ever taken off? I doubt it.
And besides, every stock on earth is bought in the hopes that it becomes popular and are sold in profit. So are all stocks "meme investments"?
That they are bought with the hope of them going up is not what makes them a meme investment, it's
why people think it will go up. You think AMZN or APPL will go up because Amazon's or Apple's business will do better. For investing in oil futures, you look at what is happening in Iran, etc.
For a meme investment, you don't look at any business or practical detail, you look at
other investors exclusively.
You can go ahead and argue that others does better when it comes to cross-border transactions and digital transactions. Yes, you're right! But, does it really matter whether it is better or not?
You are correct, it does
not matter.
That's the whole point of the OP! Now you get it.

You invest in Bitcoin because you think more people are going to invest in Bitcoin than are investing now, not because you think the product is going to grow in practical value. That's the definition of meme investment.