The issue is his body is clearly falling apart. He's 29 and can barely play a string of games due to injuries and they are getting worse. The more injuries he picks up the more he loses this ability you want him here for. It's highly likely judging by his injury record that soon he'll lose his explosiveness and/or top speed. All players get slower, this can be down to fast twice muscle fibres degrading as you age or culmination of injuries meaning your body just can't do what it used. Bale has had more of these injuries than most. We can't sign a 29/30 year old on 300k a week who would be dropping off naturally anyway (let alone with Bale's body) who's only asset is his physicality, when that very trait is likely going to be gone within a couple of years (if not already). We're then left with Rooney mark 2, a 30 year old on massive wages on a 4-5 year contract.