Sorry dude, but your definition of nice living doesn't jive with reality. I have friends who are professional footballers in the 4th tier of English football and they have jobs in the summer as well. They are paid $40000 at the absolute most and their career will last maybe 10 years.Pay scales and the rules that are beneath them are complicated due to contracts and other legal issues, and thus hard to compare.
There are no academies as their are in soccer or other sports. Everyone is trained where ever and become eligible to turn professional at a designated age, usually about 18 in baseball (with some important exceptions), and 19-21 in other sports..
Suffice it to say that Dansby Swanson, a 22 year old college player, was the first draft pick (ergo the best amateur player) in 2015, which means he is exclusively available to negotiate and sign with one club during the year of his draft, namely the Atlanta Braves. His remaining options (same for other drafted players) if he doesn't like the money offered or the team that chose him are fairly limited; he has to wait for another team to draft him. Leagues in other countries won't take him (they will take basketball players in similar circumstances). In effect, the drafting team and the drafted player are locked into each other for a year.
This is not too bad if a player can go back to school for another year, but it is complicated if a player has graduated from college and can't go back there. If he chooses to play in an independent league, he could get hurt and miss out on the big money.
But the point of an inverse-to-last-year's results draft is to establish parity by preventing the hoarding of talent as happens in world soccer and in particular in the Spanish and English premier leagues (where the same kinds of laws that permit drafts don't exist).
All sides recognize parity is good for everybody, and the upshot is that the penalty on pro teams for restricting the movement of top amateur players is a negotiated agreement with the players' union that requires teams to pay its top few drafted players some minimum amount of bonus money collectively. In some respects, the top draft picks are competing with each other for that pot of bonus money in signing negotiations, and sometimes that becomes a problem, but usually not.
While the top draftees get big bonuses, lesser players, non-drafted players and youngsters from places like the Dominican Republic where the players are not subject to the draft get far less and many of them are indeed struggling to make ends meet. Many coach privately during the off season for extra cash.
Also, it is important to note that any number of drafted players don't project to have the talent to make it all the way. Those guys are place holders -- essentially the practice squad -- and they change year after year for there's no sense making a guy wait for years and letting him dream when he is only going to be a practice player with no shot and should start getting on with his life outside of baseball. With that kind of turnover, the league doesn't have to pay much for their services.
I don't know enough about cricket but in soccer, a guy who doesn't project to being in the EPL can still make a nice living on a fourth or fifth division team without being a hanger on. That's not the way it is done in pro baseball in any country that I know about. So that's the apples and oranges of "length of career." The historic average is that each MLB team finds room for three or so newbs a year from amongst the hundred or so of guys they sign and cut every year, and most of them don't last too long because of injury, competition and deals with established players.
Cricket also has nothing similar to that, there are 1200 members of the MLB players association. If there are half of that in the cricketers association I'd be amazed. There is more opportunity and money to play professional baseball because US is a bigger country, which makes sense.