I agree with much of what you wrote but the big difference here is that Jones is fighting for a spot in a top club. The likes of Lallana, Ox and even Henderson played regular football at Jones age.
And where does he actually fit in?
He's a winger turned midfielder. He takes too many touches and is far too slow to play on the wing.
Not sure about the Thiago comparison either, I mean there were signs that Thiago was world class last season even though he wasn't consistent. The lack of Fabs in midfield also didn't help.
You can either focus on the positives or the negatives. Yes, he is a winger turned midfielders, takes too many touches, and is far too slow to play on the wing.
Henderson was exactly in the same boat. A not so good right midfielder plus winger who reinvented himself as a central midfielder. Jones can do the same.
Jones has a number of positive technical attributes. I bet if he plays regularly he will outperform all of our midfielders on dribbling, shots taken on goals, and goals. That is a base we can build on. He is a youngster learning a new position.
You missed the point about the Thiago comparison. Thiago was a 10-year veteran who had won multiple trophies. There were signs of class last season but it took him a full season to become an unquestionable first-choice starter. When we bought him and paid him 150-200K per week wages, it was to make an immediate impact and upgrade our midfield instantaneously. If we are willing to be patient with him, why not with a youngster who is still learning his craft and is probably on 20% of Thiago's wages.