This man, Mark Garaway, his coach as a teenager, has so much to answer for:
"I asked Jos to start keeping wicket as well as batting. Jos initially was reluctant, didn't want to risk his fingers and we had a number of 'grumpy' sessions.
Over time, Jos saw some merit in what we were asking him to do and he started to keep wicket with a smile on his face.
Or at least a grudging grimace.
These humps were vital to his development and show that success is never a smooth path."
This man, Mark Garaway, his coach as a teenager, has so much to answer for:
"I asked Jos to start keeping wicket as well as batting. Jos initially was reluctant, didn't want to risk his fingers and we had a number of 'grumpy' sessions.
Over time, Jos saw some merit in what we were asking him to do and he started to keep wicket with a smile on his face.
Or at least a grudging grimace.
These humps were vital to his development and show that success is never a smooth path."
https://www.pitchvision.com/the-buttler-factor-how-extreme-talent-identifies-itself
And that's how Somerset ended up losing this extraordinary batting talent, and how England ended up in the extraordinary mess you describe.
It's incredible how many players are asked/forced/convinced to be keepers, but so many of them never master it because it's not the thing they love.