Did the tensions between Dave and Steve Winwood held the band back fulfilling its potential?

https://www.guitarworld.com/artists/guitarists/dave-mason-obituary

'“After cooking an amazing dinner with his wife, Winifred, he sat down to take a nap with his [pet dog] at his feet. He passed away peacefully, in his favourite chair, surrounded by the beautiful Carson Valley that he loved so much. A storybook ending. On his own terms. Which is how he lived his life right up to the end.”'