Golf is the most frequently used comparison for tennis because they have a nearly identical tour structure and calendar, with golfers also being individual athletes like tennis players. Yet the PGA pays golfers 30-35% of tournament earnings, versus 10-15% in tennis. So even if we discount the major team sports and their near 50/50 split between teams and players, golf is still paying their athletes 2-3x more than tennis.
And to the posters who keep going on about second-division Spanish football teams and their devoted fanbase, please look at the global viewing numbers for tennis tournaments. You're comparing a local market team and their ability to put 20 thousand fans in a stadium once a week and get good ratings in a tiny local market, versus a tour that gets broadcasted in nearly every country on earth, pretty much year-round, for hours every single day.
A majority of sports revenues comes from television deals. So a company like ESPN pays the ATP, ITF, and slams hundreds of millions of dollars in order to have exclusive rights to their matches. Subsequently, ESPN sells each 30-second commercial during those tournaments for tens of thousands of dollars (depending on ratings, a single 30-second spot can cost hundreds of thousands for a big name final). Tennis also draws a very affluent audience, so those tv spots cost even more, exceeding $50 per thousand views at times. It's why you see companies like Rolex, Mercedes-Benz, and every other luxury brand advertising during tennis tournaments. When in factor in sponsorships (also high-value due to the prestige, affluent audience, and implied endorsement from a prestigious tournament), tennis ends up being some of the most desirable advertising inventory that luxury and aspirational brands can buy.
I'm not going to research the numbers, but I wouldn't be surprised if the total revenue from the year-long tour (tv deals in every country, global sponsorships, local sponsorships, ticket sales, executive suites, food & drink, etc) surpass a billion dollars annually. And the tournaments get to keep 85% of that. It's absurd, to the point where tournaments are willingly taking fines just so they don't have to disclose their earnings. The tennis infrastructure certainly isn't more complex than golf's, so why is the PGA paying their athletes a share that's three times as large as tennis'?
The reality is that it's pure, unadulterated greed. The people at the top have gotten used to getting rich by exploiting tennis players, keeping them in the dark with regard to their true value and worth, and promising change that's perpetually in the "process" of being addressed. Meanwhile, only the top 20 players on tour make a living that's comparable to minimum salary in the NBA. When your #50 ranked player is struggling to break even and a missed year of play very well could end their career for lack of finances, your sport is in a shït state. The sheer number of smooth-brained idiots in this thread who are looking for every nit to pick just so they can satisfy the status quo of a rich executive class and a handful of top athletes thriving while 95% of players are being paid a pittance is disgusting. The system is broken. All players but the top are getting fückęd. Look out for your fellow working-class human and support them in this endeavor.