In between 2016 and 2018 the likes of James Vince, Tom Westley, Dawid Malan and Nick Compton all got opportunity in the Test side at varying positions from no.3 to no.5 with varying degrees of success but not really nailing down the spot (you could argue Malan did a bit). I may have missed somebody too.
This was Hain's opportunity with the spots available and coming off the back of a strong 2014 and 2015.
He averaged something in the 20's in 2016, 15 or so in 2017 (imagine the stick he'd have got in here these days..) and about 30 in 2018 in div 2 (I remember he never made a ton that year.).
He missed the moment I think.
Since then, particularly since 2022, he's been absolutely elite. Totally phenomenal. Unfortunately Jonny Baitstow had a renaissance of sorts in 2022 then some bloke called Harry Brook became a superstar whilst Joe Root went from good strength to incredible strength.