There are enough MLB sets already. Topps has two or three releases hit shelves every month during the season, plus they have all of their online products. I remember not too long ago when every week would see two new lines arrive at the card shop. That's just too overwhelming.
But it's not just about the number of releases.
In 2011, sets like Gypsy Queen were really short-printed due to a perceived lack of demand, and even Update was probably printed in much smaller quantities than in previous years. But tons of 2018 Update packs have flooded clearance bins at Big Lots and WalMart; the last cards I remember at Big Lots were 1990 Donruss! And the baseball cards subreddit is full of investors looking for profit and hoarding these packs; it's almost like we're repeating the mistakes of the junk wax era all over again. Just now it's with certified autographs and SPs of unproven rookies, instead of base cards of unproven rookies. (How many autographs did Guerrero Jr. sign this year?)
Don't get me wrong, as a budget collector, not a prospector/investor, I'm more than willing to pick up the "scraps" from these big spenders looking to clear out their "worthless" base cards, inserts, and parallels. And I'll be glad to swoop in and pick up all the other "worthless" cards people have if the bottom drops out. But we've had this before. And too much product out there will lead to disaster.
Apples to Apples? Topps' flagship has 15 parallel inserts as well, but their insert sets have only 5-6 parallels each (still a lot, but not as many as Donruss). Many insert sets only have three parallels. Chrome has 19 base parallels, but autograph sets generally have less than six parallels, with only the Rookie Autographs having 13 parallels (printing plates count as one set). Finest: 8 parallels of the base set.
So, why do you think Panini shouldn't get an MLB license? Remember, arguments for them getting a license should go on the other post. This isn't about a flame war.