A $1T founder is rewarded for building a massive system that employs hundreds of thousands of people, moved technological progress forward dramatically, and has positively affected the lives millions.
A doctor provides life-saving care, but they are physically limited to helping one person at a time. A backup NBA forward might not save lives, but their work is broadcast and monetized across millions of screens at once.
Arguing that entertainment is "non-productive" ignores human nature. People gladly pay to be entertained. If sports have no value, do you feel the same way about books, art, and movies?
Probably the highest paid athletes in the world are european soccer players and the thing there is that these salaries can be justified in terms of the value top players bring in a game where being relegated can bring the money train for a team to a halt. You don't see working-class soccer fans complaining about this (they feel the value!) but the owners and many representatives of capital get fuming mad about it.
(Funny, growing up in youth soccer in the US taught me to think of the game as an exercise in Brownian motion where there are too many people on the field who aren't held accountable. It wasn't until I had an argument with a recommender system that couldn't accept that I hated soccer that changed my mind and turned me into one of those sports fans who rolls out of bed Saturday mornings to watch the Premier League that I realized how high the stakes are in the European game.)
Acting is about art, which brings up different issues and value. But looking at broadcast sports, the marginal value of doing that work is still zero: If that person didn't play football, someone else would and the entertainment benefit would be the same (excluding the few extraordinary athletes like Messi).
If there was some accountability those teams would be better or would be playing at a different level or not at all. So I'd argue pro/rel is a net plus because it leads to better play. Personally I watching the New York Red Bulls (Major League Soccer) play in person but overall soccer is the US is not up to international standards.
What blows my mind about soccer in the UK is that interest is so great that they can support two leagues below the Premier League and I know there are leagues below those. When I went to the Cornell/Syracuse game which is a legendary matchup that attracts a lot of youth players in the audience I was just thinking of the depth and width of the pyramid of soccer play from Kindergarten all the way to the world cup which is what makes the soccer universe so compelling. (Kinda wish more of us enjoyed college soccer!)
From a sports perspective, sure, I agree. I've often thought that the only non-competitive position on a sports team is owner. If anyone else, coach or player, performed for one year like the some team owners do for decades, they'd be out of a job. Owners won't agree to losing their jobs (fire the bottom 5%?), but relegation ... but would the other owners want the biggest market, for example, relegated?
But this discussion is about societal value. Whoever wins and loses, every game is net zero in entertainment value (whatever that is worth): 1 win and 1 loss. Every relegation is net zero: one team promoted, one relegated. Every championship: 1 team wins, another finishes 2nd, etc., no matter who it is.
The $1T business owner doesn't provide nearly that much marginal value to society.
The backup (or starting) NBA forward provides zero marginal value - if they didn't do it, someone else would and the outcome for society, entertainment, would be the same. It doesn't matter how well they play basketball; that doesn't make it more entertaining (with a few extraordinary exceptions). People in the US enjoy college sports, where performance is much worse, as much as professional sports. People root for their 'bad' local team as much as a good one: they do prefer winning, but that is a zero sum tradeoff with the other team's fans.
The income for the two examples are the results of economic distortions.
My kids' teachers provide contribute far more than the latter, and far more than they are paid.