This is really nothing new. Cards have always been an investment (at least for the last 40-50 years). As I view things, the casino-level action that inspires modern is a symptom of a speculative bubble, not an end in and of itself. People who get into trouble bubbles conflate the two every time.
I don't think there is a serious debate to be had that a sizable percentage of newbies are engaging in a form of young player/new card speculation that has a long track record of failure. The cabinets of longtime collectors are littered with the cardboard images of flashes in the pan, from Ron Kittle to Kevin Maas; we've all got piles of junk (damn you Keston Hiura). Pete Reiser and Herb Score Tony C., we feel your pain with our stacks of your cards. Most prospects will go sour, as will their cards. There is no reason to believe that the people speculatively accumulating cards of shiny new players will have a different outcome than everyone else who followed that strategy in the last 40 years. What does stand out today is the steep trajectory of the price increases and the resulting incredible sums at risk, so much more than in any other rookie card run. I don't really care that the twenty bucks I put into Topps Walgreens yellow Hiura cards is gone; I would be shitting egg rolls if I'd spent thousands on a signed shiny limited edition thingy. The scary thing about modern is that there are tons of very expensive signed shiny limited edition thingies that place really large sums of money at risk and that new ones come out practically every week.
There is also a meme component to it. Lots of peers valuing these cards so they go along to get along, and market be damned.
From a financial perspective, I am not sure the newbs understand that the hobby is a particularly brutal investment when it comes to new players and modern cards because the bet can go to zero very fast and there is no hedging or exit strategy available. Even in a falling stock market, you can set a stop loss and get out, and real estate never goes to zero, it cycles, but when Sam Horn goes down the tubes there is no exit and no bottom except the commons bin. Babe Ruth does not go down the crapper the way the latest, greatest thing will when his WAR falls to 1.8 (yeah, looking at you, Pete Alonso).
Kids are always going to get into the current stuff; we all did. I was abuzz every year with the latest offerings from Topps, and crazy to get that rookie (I recall 1976's Willie Randolph and Ron Guidry RCs with great fondness today as the young stalwarts of the first Yankees team of my childhood to win a pennant). Man, how I chased those cards. A percentage of those kids trading cards will study history and become intrigued with the past, like all of us did; no one is born with a desire to buy a Harry Hooper card. They always do, and the 'boring' cards from 100-150 years ago will come to life for them and that itch will start. First it is the Mt. Rushmore players: Ruth, Cobb, Gehrig, Robinson, etc. Then, it is the next tier down, and so on, until they are chasing regional Claude Osteen cards for their Dodgers franchise collections. It is the journey of a lifetime of collecting.