Your whole post is hilariously wrong.
The Tour is the biggest race of the year, but you're downplaying the importance of the classics and the other big stage races massively. Paris-Roubaix and Ronde van Vlaanderen especially are massive races that riders would probably kill for if it meant they had a chance of winning. The Giro, the Vuelta, Liege-Bastogne-Liege, Il Lombardia, the World Championships, Milano-Sanremo, Amstel Gold Race and Paris-Nice are also races that can make a rider's career if he just wins one of them once. For the most casual viewers the Tour is the beginning and the end of cycling, but for people that actually follow the sport there are dozens of very important races. I know people who only watch football when the World Cup is on and couldn't give two shits about the rest of it who think that the Premier League or the Champions League are irrelevant tournaments. That's what you sound like when you discredit everything apart from the Tour.
Also, cycling is a dirty sport, but it isn't the most laughably dirty sport. Athletics is most likely the worst by far, and American football and baseball are also really bad. Cycling has a bigger reputation for being dirty, and thus there's more testing. More testing means more positive tests, but it doesn't necessarily mean more doping.
And doping is only doping in an ethical sense. In terms of how effective the different substances are there's a world of difference. Give one rider amphetamines and another rider EPO and the guy on EPO wins every time. Amphetamines makes an already good rider slightly better by giving him more energy and a higher pain tolerance. EPO can take a complete amateur and turn him into a world beater, and it has nothing to do with cycling talent and everything to do with how well the individual rider responds. We saw it in the 90's with guys like Riis, Chiappucci and Berzin who were mediocre at best without EPO. Even Lance was miles away from being anywhere near winning a stage race until he got on an EPO program. Lance became the best because he responded well to a particular substance. Merckx didn't need EPO to win anything. He was already the best, dope or no dope.
Oh, and any athlete can only beat the competitors they're up against. Pelé is still considered by many as the greatest of all time even if he played during the 60's and footballers have gotten better since. However, in endurance and power sports there has actually been very little progression over time. The only reason cycling was so much faster in the 90's was because of EPO. Merckx, considering the equipment he used, posted an hour record that only a handful of riders today would get close to, so put him into the peloton today and he'd still be great, if not as dominant as he was back then due to a higher degree of rider specialization.
To put progression of athletes into perspective: Jesse Owens was only about half a second off the pace of the best sprinters today, and he ran on dirt tracks that he had to dig holes into to use as starting blocks, and didn't have access to the steroids sprinters use now. Humans haven't evolved to become better athletes in the past 80 years. Sports just has better equipment, better dope and more money now.
