You just noticed that camera phones don't actually show you the image. Camera phones create a computational model for what you see, and then use that computational model to create the individual pixels.

I think there are two major reasons why this is the case: low light and zoom.

Most cameras don't have continuous optical zoom, but most users demand continuous zoom. In some cases, a secondary camera with different focal length could help a bit, but that suffers from three problems: (1) it only gives two distinct focal lengths and not the continuous zoom that users demand, (2) it has parallax error, (3) the zoomed-in camera can't be achieved with a longer real focal length since real focal lengths are as much as phone thickness allows, so it's achieved usually by a smaller sensor (even larger crop factor, creating lots of noise even in decent light). So to allow a reasonable continuous zoom, what cameras need to do is to create a computational model for what you see in the picture, then use that computational model to recreate the image at the zoomed-in resolution. I suspect the manufacturers "for simplicity" use the same image processing pathway even if you take an image at 1:1 pixel mapping. Otherwise users might complain that the image style jumps from "real" to "painting-like" if you even zoom in a tiny tiny bit.

Secondly, the low light performance of small camera phone sensors is horrible. In photography, "low light" means basically everything except outdoors during daylight. Yes, with a camera phone sensor you can't take a reasonable image indoors even if your ceiling has lots of very bright lights. Even the flash doesn't help, since camera phones don't have a real Xenon flash but rather a feeble LED light that only helps in about complete darkness, or if taking a photograph of a receipt 30 cm away.

This means that camera phones as-is are about useless in most situations where they might be used. To solve these issues, camera phones have to have so high amounts of denoising that no DLSR or mirrorless camera would need that insane denoising amounts. So they do the denoising with lots of artificial intelligence on a fast processor that has special artificial intelligence capabilities. I suspect that denoising is used "for simplicity" even if it isn't strictly speaking needed, like in bright sunlight.

Those computational photography algorithms seem to often create a painting-like image, not what you would see with your eyes or in an image taken by a professional camera.

Finding if there's some way to shoot RAW images without the computational photography could help, but only in direct sunlight as the noise in those RAW images would make them useless in about every different situation.