But this has been an evergreen complaint since I was in my early teens and first noticed it. Perhaps it's been a complaint for longer.
When I was in my teens, the issue was that a number of countries that didn't have professional teams per se provided very large subsidies for mostly nationalist reasons to those who represented their countries. These might have been very reactionary but mostly were countries with highly centralized, command-and-control economies like the USSR or China. It pushed standards higher for self-supported athletes in other countries, and got government subsidies for a lot of Western athletes.
In many cases, companies provided money. Often for fairly piddling sorts of publicity. But as the willingness to support the country's image decreased (and a desire to be supported in every way possible increased) that went away. You either need a lot of publicity to be able to sell more stuff or what's the point. You get nothing but hate for corporate charity unless it suits very particular agendas, so either it makes you a lot of money or it's an expense of no use.
I like the original idea of the Olympics. However, it made it a thoroughly bourgeois event. As long as athletes were in it for fun, for competition and sportsmanship and just bringing people together, it worked fairly well. Once it was reduced to a mouthpiece for Soviet nationalism or national pride writ petty, it became just another commercial sporting event with governments in the role of corporations in many cases, even "socialist" governments. And with that came all the corruption that follows any concentration of power in a centralized authority staffed by humans.