People produce less text with more errors in more time on mobile. I actively avoid having to type anything on mobile. If I have my laptop open, I'll use whatsapp or signal on that. I often wait replying on either of those until I get my laptop. Just way less frustrating to not have to correct >25% of my key presses. If I have to use the mobile keyboard, I'll often just send a message with typos, no capitals, and skip some of the more redundant words. It seems lots of people do that. Phones just suck for text input. Longform text entering on a phone is by and large not a thing for most people. It's mostly a read only device for passively consuming news and media. And taking photos.
I find it telling that one of the more popular addons for ipads are covers with a builtin keyboard. It's a way bigger device than an iphone. But yet the keyboard sucks enough that Apple sells covers with a keyboard. Of course, all the touchscreen keyboard problems that the ipad has are magnified on their iphone. Yet, they don't have a solution for that. And they also sell a stylus for the ipad. Because fingers lack precision. It's the same OS but there seem to be no such options for the iphone. Does the stylus even work with an iphone? Is that deliberate? It's not like people are going to be magically more precise on an iphone relative to a huge ipad. Conclusion, Apple just accepts that that's the way things are. And besides, Steve Jobs would turn in his grave if they dared to ship an iphone with a stylus.
Hardware keyboards on phones used to be a thing. I worked at Nokia back in the day. Really nice keyboards. Blackberries were popular too. People wrote lots of stuff on those things. I wouldn't mind a little pocket laptop. It's not like my pixel 6 is small or subtle in my pocket. It would be more useful with a slide out keyboard.