I think there's a lot of truth in what you say, but Gazza isn't in the category of ''needing to sort his life out'' - the guy is seriously mentally unwell - if we choose to believe his self-reporting. I think I can say that without excusing his domestic violence stuff too.
And there's an opposite argument to your player fitness points too. Le Tissier was a ridculous talent, a lot of current EPL attackers aren't anywhere near the same class. not even close. 20+ goals a season for consistently serious relegation candidates Southampton - admittedly only the seasons he could be bothered, but even so.
And some people (quite a lot, I think) seem to rate Gascoigne extremely highly - just under the top sphere from what I can tell. Which is maybe getting a bit excited & probably requires the use of some of the 'excuses' on the footy assessment side.
(And I was never quite sure about Brucie in the 90s tbh -
)