"Necessary" was probably too strong a word. I'm definitely no expert so I can only offer anecdotes, but for the first ~decade of iOS, the keyboard felt amazing to use. I felt super fast and typing mistakes were rare. Now I feel like I'm constantly fighting the keyboard to type the letters I actually want to type.

Agree at this point that I would disable it (in its current state) if I could, but when it worked correctly it was a huge boon to typing.

Ok so it's not just me. I never had predictive text enabled but stopped being able to type easily when I switched from iPhone 5 to 12 mini. Thought I needed to get used to the new phone, but it's been years.