I think you're falling into the trap of using our midfielders (and particularly Naby Keita) as a benchmark. It's not been the most productive area for us since Coutinho left, but if we're looking for improvements then we should absolutely be setting the bar higher. Personally, I would much rather give minutes to Fabio and Harvey than spend a fortune on JWP (let's face it, he's 28, English, and Southampton's talisman - it would take a hefty fee for them to let him go). If you take out penalties, JWP had 6 goals and 6 assists last season. And 5 goals and 7 assists the season before that. Appreciate he's in a poor Southampton side, but I think both Fabio and Harvey would deliver better numbers given the same game time, and have a much higher ceiling to boot.
Funnily enough, when you compare JWP's and Keita's contributions per minutes played last season (given that JWP is an automatic starter and played nearly three times as many minutes as Keita), there's not a great deal in it.
https://www.squawka.com/en/comparison-matrix/?compare=mL3Ec-q8v2SLhP7zdOnlr