And no, a lot of players don't sqaunder their money on 'mansions', etc. I would be willing to guess that the financial woes of former players happen at a rate not much different from anyone who gets a lot of money in a short time and doesn't sustain that income. See - musicians, lottery winners, etc. A lot of them are very business savvy, including endorsements and aren't just 'making it rain' every night.
And NIL is a new thing - you've got programs bringing in billions of dollars in revenue and coaches earning millions - all on the backs of kids. Some of whom, it's been documented, often don't have enough to eat and some who've slept in their cars. D1 sports like football have been exploited by the networks, etc as a profit factory. It's not exactly the wholesome student athlete paradigm that was presented for years. A lot of players were earning money before NIL - sometimes they got caught (see Eric Dickerson). At least it's out in the open now.
As far as the players being greedy - we go round and round on the same debate. Players are paid what the market dictates. No more, no less. The owners - who are all super-wealthy by the way aren't keen on just throwing dollars into the wind to satisfy the 'greed' (funny you use it only for football players) of their players. These salaries exist in a financial structure that's controlled and agreed upon and part of a balance of money out and money in.
If you want to point out 'greed' how about Tom Brady getting 100 million dollars to watch football and talk.
