Just trying to place the caret anywhere other than the end of the input field is guaranteed to cause frustration.
I frequently give up on writing things on my phone, saving them either for when I am at a computer with a real keyboard, or just not at all in many cases.
Still not great, but do you know about the spacebar trick? Anywhere the keyboard is open in iOS or iPadOS, press and hold the spacebar. The keyboard is now a trackpad and you can easily move the cursor. Incredibly bad discoverability but has been a big qol improvement for me.
I frequently give up on writing things on my phone, saving them either for when I am at a computer with a real keyboard, or just not at all in many cases.