Can't you connect one to your phone?

Yes, but that requires carrying a separate device, which makes it too inconvenient to use casually. I want the keyboard to be built into the device itself, like you used to be able to get.

There are keyboard cases like https://www.clicks.tech/ which attach to your phone directly.

This. Much of my typing speed and accuracy comes from feeling the positions of the keys. I can't do that on a touchscreen phone. They are so error prone and frustrating. Autocorrect is almost useless.

One just came out. Only one on the market I know of. It's called the Unihertz Titan 2, and I'm typing this comment on one. It's got a blackberry style keyboard and runs pretty close to stock android. I recommend swapping their default keyboard out with swiftkey, though the default one isn't terrible - swiftkey just gives me a few conveniences like emoji suggestions. It has play services, so it works.