Seems like a chicken-egg thing, though, no? Does Miami have an unfair advantage getting Cuban players, and are just not interested in spending money? Or didn't attract the first good one, that would create the chain reaction? While I agree with you in terms of the effect, I'm not sure about the cause being an issue of unfairness. Players are people, who have a right to go where they want, and it makes sense that once Ohtani went to LA, they would have an advantage even over the other west coast teams, especially considering that they are ALSO offering the biggest market, the most money, and the best chance of winning a World Series. Can you blame the players for choosing that situation? And really, do you want to blame the league for allowing them to do what they want?
It's a tough balance, where as fans we want to think that competitive balance is important, but only because our team isn't the one getting the best players right now. When the Sox were consistently a top-3 team in payroll, there wasn't a lot of complaining around Boston that a hard cap should be instituted. It would take an international draft system to fix this, but that feels like a very anti-labor solution to me. Sasaki made what feels in retrospect like a preordained decision, but it was his choice to make. The Dodgers have made themselves the preferred destination for the current generation of top Japanese players, but there are also so few of them. If the Braves attracted a few top Dominican players, would we have this same discussion, or not notice because the pool is larger?
I think the issue with Sasaki is much more an issue with how MLB handles international free agents and the differing treatment by age/experience/country/etc. Like, I think your point is fair - baseball teams geographically close to international hot beds will typically have an inherent advantage for some - maybe many, international athletes with a true free agency to pursue.
But Sasaki isn't a free market negotiation, his age and professional status pretty much caps every team to their international free agent spending pool so Sasaki, who is pretty much universally considered a potential top major league talent right now, is "competing" for the small volume of money in each team's IFA Pool that is usually spent heavily on 16 year olds from Central and South America. So in reality, Sasaki doesn't glean any advantage from the most money, which does take away any real negotiating advantage from other teams
because the Dodgers spent a billion dollars on Ohtani and Yamamoto already (and they chose the Dodgers). Now, we don't really know the Dodgers true cap. They might have thrown 500 Mil at Sasaki too, but the inability of Sasaki to pursue a true free agent contract OR be subject to the draft really gave the Dodgers a huge advantage in this particular sphere.
But yeah, I don't think Sasaki is a Dodgers thing directly, any team would be insane not to be willing to empty their pool for the guy, and that he was able to just not take meetings from a ton of teams say front offices agreed on this. But when you take away the financial incentive for a pro-ready player, this is what will happen.
In terms of the international draft, I do think it needs to be considered somewhat more holistically here. Yes, it's more anti-individual labor than the posting system in that Sasaki can't choose his location directly (though he could absolutely refuse to sign or play hardball that way), however, the Sasaki posting negotiations is anti-labor for a lot of other parties. Namely, the Sasaki pursuit functionally forced any team who was seriously pursuing him to put their entire IFA Class on hold. There are three teams who had not signed an international free agent when the international signing period opened -
the Yankees, the Blue Jays, and the Padres - three of the end-game finalists for Sasaki. This means the top names either signed with other suitors or, perhaps, they may still be waiting to lock in a deal. Manny Cedeno waited and seems to be a Yankee, De La Cruz and Alvarez with the Padres, Polanco with the Blue Jays, so some prospects waited, but the Dodgers likely had a few names they left behind in that pool as part of their scouting and others may have agreed to deals with other teams to lock in immediate wealth and not take that risk. We will probably never know if Cedeno was the top Yankees target anyway but the presence of a name like Sasaki upends signing classes of players and I would not be terribly surprised if prospects that Dodgers had soft/verbal agreements with experience a pretty serious negative experience as every other team spends their pool money and the Dodgers can't make that end meet.
Would an IFA Draft - or at least a separate prospect for posted Japanese/Korean pro ballplayers separate from the amateur international free agents - be more or less or similarly fair? I really don't know, but I do know that this system made Sasaki to the Dodgers an inevitability.