TBF, he's got 2 goals in 381 minutes. Tally is similar to last season, roughly 1 goal every 2 matches, even though he's played in a more sporadic role off the bench.
In terms of actual G+A and everyone's favourite xG+xA/90, he's roughly equal to Kudus in production. They're basically inverse of one another, Kudus is biased to assists and Johnson is biased to goals. Obviously Kudus contributes more off the ball, and rightly should be playing*.
In this moment where we're struggling to play through the middle, and we have a first choice RW that can't score for love nor money, we could do a lot worst than playing Johnson as second striker and have him making those runs in behind.
Johnson has a talent for scoring goals. People spent years picking Kane apart as a tap in and penalty merchant before the narrative finally got played out. The reality is the most difficult thing to do on a football pitch is score - throwing away players who have proven the ability to do that is foolish.
*This is another issue with some supporters. We need depth, the same 11 can't play every match, all match. Even if Johnson isn't "good enough" to be first choice, he's still contributing more than most anyone else. Player movement needs to be targeted and strategic - if we're replacing a player from the forward line, it should be Odobert first (though I would advocate for a loan due to his age) and Richarlison second. Do that and Johnson shuffles down the order, then maybe he's on the chopping block. But I'd still probably loan Tel put and replace him with someone as my third forward move, so Johnson's spot is, at best, 4th priority.