Football skills have nothing to do with deep tactical understanding or knowledge of the game. One of the biggest misconceptions casuals have.
Many legendary Footballers are very dumb off the pitch which is why they miserably failed as managers. I really don't see R9 as the kind of "professor of Football" type a Xabi Alonso clearly is. This is a guy who struggles to watch full games, in his own words.
Let's take an example, R9 is way better than Pep as a player but Pep understands Football way better than most GOATs combined. Are you telling me R9 understands and dissects a game of Football better than Mourinho who was never a pro? The likes of Klopp and Wenger understand the game way better than Xavi.
Many Football fans, commentators and journalists understand and analyse the game way better than some of the best players. Majority of the Footballers are actually very dumb, which is reflected in their interviews and scandals off the pitch.
Many of the pundits(ex pros) say the most generic shit ever instead of proper nuanced insight. There's a reason why YouTube fan channels are overpowering legacy media. So while it sounds absolutely batshit crazy, it's likely that Birdy analyses games better than Ronaldo "Football is boring, Tennis is way better" Nazario.
Exactly, said it many times. Intelligence and critical thinking skills are more important in analysing football, than actually being good at football.
For instance, Ferguson, Pep (great player but not an all-time great) and Mourinho are miles better managers and coaches than Maradona or Pele ever were. Going by logic such as 'best players are best critics' Maradona would have been an amazing coach.
Then, as you say, pundits talk nonsense all the time despite being great at football. There's nothing worse than when an idiot, clueless pundit like John Terry, Alan Shearer or Rio Ferdinand says they know more because they have played the game.
It's very rare someone is both amazing player and coach. That is what makes the likes of Cruyff and to a lesser extent Beckenbauer so special.
It's about intelligence and critical thinking skills. No amount of playing football gives you the eloquence and tactical understanding to analyse a game as a watcher. I was actually surprised Xavi was a relatively poor coach for Barca, as you'd assume someone with his deep understanding of the game as a player would become a good coach. But it didn't work out that way. Alternatively Alonso and Arteta are currently thriving.
R9 is one of my favourite players ever, but he doesn't seem too bright in general, and like Ronaldinho he seems guided by emotion. Being an amazing footballer doesn't mean you are an amazing coach.
In saying all this, I can fully understand his perspective that football was more enjoyable back in the day (I enjoyed it then and still enjoy it now).