Ravens waived WR Diontae Johnson [Claimed off waivers by Texans]

Next season he will play as a 29 year old. Not the kind of guy you rebuild with, unless he's a cheap veteran who is willing to lose and play the role of teacher. I doubt any of that fits Dionte or his wishes.
His age is OK as a receiver. You're likely right about his motivation, being a team player, etc.

He can help someone. But Johnson has to get his head on right first. Without that, he's going to get only tepid interest.