I’ll try and make a serious but inevitably somewhat rambling reply to this.
It depends what you mean by “peak”. The standard of pretty much all sports now is higher than it ever was. People are not claiming that sport of 30 years or 50 years ago is a higher standard than it is now. It isn’t. The players are fitter, the money (in professional sport) earned is greater, more time is dedicated by sportspeople to their craft and it’s more scientific. The coverage is far more comprehensive.
But in a way it’s these very advances that have turned people off. Sport seems so much serious and formal now - and yet that seriousness has made it seem less serious to the average punter - or less connected. Less connected in that most sport feels more a branch of the entertainment industry than something rooted in community and society. I think anyway. I think all sports seem to be drifting away from something rooted in community and society to being something more disconnected, much more corporatised, and predictable.
What a lot of people imagine as the “peak” of sport is when it was at its most enjoyable - not necessarily the most innocent - because the most innocent time was the 19th century, but where there was at least a certain feeling of innocence. It was the very informality and often shambolic nature of ye olde sport that created the connection and made things feel more serious to the attendee or viewer. It was the connectedness. It was the communality of culture. The accessibility. The idea of 135,000 people standing together in Hampden Park, the idea of Hill 16 and banners and flags and scarves, or the shot of the Lansdowne Road end after Ronnie Whelan scored against the North in 1989 singing Que Sera Sera. The key factor which made that image so powerful was that everybody on that terrace was packed in like sardines standing together, focussed on nothing else except singing and raising their scarves or flags or inflatable bananas above their heads.
You mention the Liverpool of Fowler. When people recall the 1995/96 season they recall it because they felt it mattered. It mattered most of all to Newcastle. There were two main figures in the drama - Kevin Keegan and Eric Cantona. The whole thing played out as a human tragedy for Keegan and for Newcastle and as the glorious return of a villain/hero (depending on your team). The Gerrard slip and Liverpool failing at the very end in 2014 played out in a similar way. These were communal events experienced communally. They’re becoming rarer and rarer.
The communality and informality is breaking down, everything is more fragmented and more cynical now. We refuse to give up the trappings of modern society like online shopping and obsession with mobile phones and computers, and yet we hate ourselves for it. Concentration of wealth is a major issue in sport, as it is in society.
If I was to pick one thing that really annoys people, it’s the GAA’s insistence on online only tickets. This puts up such a mental barrier to entry. It turns people off in a visceral way, in a somewhat irrational way, but in a real way. It makes people grumpy and discontented, dissatisfied, cynical. It weakens the emotional bond. Emotional bond is everything. There are so many small things of this nature that are weakening the emotional bonds to sport among the public.
There are exceptions and anomalies to this sort of view and obviously you can pick holes in it - for instance Gaelic football was very predictable between about 1973 and 1990 - but I think it’s more true than not.
I could probably write 10,000 words about this but I prefer to bore people in pubs with those 10,000 words.