Not saying everything is easier now. You have to be very fit to play in the modern game, that is for sure, considering the pace of the game and the number of games played. But materials, pitches and footballs, are much easier these days. From passing the ball, to shooting, to lobbing the keeper, all is much easier when with a very light touch you are able to accomplish it.
But it is also a fact that average distance covered nowadays is much more compared to 80s. Workrate of players increased, a lot of players are extremely fast, a lot are built like a tank.
Old days, players used to smoke packs of cigarette per day, drink, do drugs like in the case of Maradona. Do you honestly see those players consistently maintaining their performance level 90 minutes in modern times? The popular theory is every great player would adapt by training more, being more professional and working harder, when in fact it is not a given. Not sure how Maradona would have done in this era, but you gotta take off your rose tinted glasses. You make it sound that Maradona would have been so much better than what he was playing in modern times. I say there are good arguments to say he may have been worse.
I remember Arsenal beating Real Madrid in Bernabeu 1-0 (Henry goal). After that match, Zidane said that Arsenal players were as if they were riding bikes (meaning they were fast). Let's be honest, the likes of Ronaldo, Zidane, Figo etc. are supremely talented technicians, but they lost to a bunch of runners (relative to their technical abilities) and Henry+Cesc. This is what modern football is.
Or don't you remember Dynamo Kiev that destroyed Barcelona? They had only one remarkable player, Shevchenko, others were just a part of well drilled physical team, an extremely fit team of Lobanovski. Objectively, very few of them could play in that Barcelona team if we were to judge them by their technical abilities. But football isn't only technique, as it was shown then.
You keep implying that people who watched Maradona wouldn't put Messi above him. I have seen LOADS of experts, analysts, pundits whatever you call them, say Messi is in fact the best ever. Graeme Souness has probably said it 100 times, and whether he was a good manager or not, he was a top player who played in that era, and he also knows football. In Spanish league, coaches have said multiple times that Messi is the best ever. One said (I forgot who was it) that Messi is better because he does what Maradona does, but much faster.
The Messi vs Maradona issue isn't a settled one, as many make it sound in this thread. Not at all. And it is not a fact that Maradona would have it easier these days.