The reason is they simply cannot do it. It's very different shipping a high end phone in units of 100 million vs shipping a high end phone in units of 500,000.

This is why most android high end devices are really tiny market share.

They can't compete with Apple-- AT VOLUME. Apple's supply chain is where they are hugely competitive. This goes for Samsung etc.

So on android, genuinely high end phones are prestige items to make android look good, but the mass of android phones are low end cheap phones that can easily be mass produced.

Apple has been known to buy 10,000 prototype modeling machines and put them into production because they were the only ones on the market that could do a particularly manufacturing step that was needed for that model... google is never going to do that.

In fact, I don't think google has ever made any phones (excluding Motorola) themselves-- all the Pixels are rebrands of other makers devices.