What was the point? You called out those that 'parrot' Fangraphs, which is a statistics based website where multiple substantial contributors have ended up in MLB front offices, and your counter is that of a paid team employee/announcer.
I'll try to summarize my thoughts on this as succinctly and without snark as possible, but with a couple caveats. Caveats: I wish the rules were different, I wish the teams were ran as public investments (a la the Phillies owners comments) vs ROI for billionaires, Ricketts and other owners should spend more than they do (and/or make games way more affordable), etc along those lines. Having said that: the reason teams hoard prospects so much is that the 5-6 years of team control at league minimum or severely depressed salaries is so uniquely advantageous in terms of team building in a quasi-salary cap era, especially when young players are showing up the majors as finished products (and hitting the downward slope of the aging curve) more frequently than ever. Yes, prospects fail more often than not. But even the slim likelihood of getting significant contributions from a guy making $650k (for multiple years) opens up so many options.
I maintain that the reason the Cubs are seemingly capped at this slightly above mediocre level isn't because of missed elite FA signings or Hoyer being too cowardly in the trading market, but because for years (roughly 2017-2022) we produced very few legitimate contributors that you could plug into your lineup without taking out a serious chunk of your budget. The team is loaded with $15m-$25m/year guys, largely giving us the type of contribution you'd expect from players getting those salaries on the open market. In an era where 85 wins gets you fighting for a playoff spot through September, it makes some sense to pay the $20ish m/year premium to go from a 0 WAR homegrown kid to someone like Taillon or Bellinger or whatever. But if you're capping out at $250m a year, you can only do that so many times. And so you value prospects, ideally a bunch of them (because they generally fail), in the hopes that three or four of them turn into regular starters (and that's putting aside the slim chance they turn into stars) for 1/20th of what you'd pay for them on the open market. As mentioned at the top, it's a dumb system, but ignoring the realities doesn't do any good.