Given that Lego lasts for decades and that my kids are still playing with bricks that were sold in the 60's of the previous century the pollution part is a bit overblown. But yes, some of it will end up in landfill, but not nearly as much as you might think compared to say plastic bags, tie wraps and other large scale plastic products.
I'm not sure Legos actually contribute much to pollution. They almost never get thrown away as bricks generally get passed down to offspring. You rarely see Legos at thrift stores as they are so highly demanded and are snapped up quickly. These little plastic bricks stay in circulation for decades and will probably be loved by humans in a century.
If kids can't even have Lego we are truly lost. For many kids, their love of science and technology stemmed from playing with Lego. You are likely benefiting now from some of those things now. I am so tired of this anti-human, simplistic, single variable optimization that so many seem to subscribe to.
What would be required in your view to establish a connection between Lego and STEM fields? Similarly, what is required to prove that there is no connection?
Consifering how much plastics we use for once in restaurants and starbucks, or how much we use in cars or home appliances and dispose (=landfill) without second thought, this is miniscule.
Do you post same question on every Tesla or Apple thread? The added value between creation and landfill is what defines utility, and I'd say Lego is one of the better uses of it. The last thing I want to see is Lego forced to use some more eco-friendly material that lasts a fraction of plastics longevity, for higher costs, and questionable ecological impact down the line.
Legos are a very creative and inspiring toy and art form. As a kid I got thousands of hours of imaginative play from them. There are far less useful things being made out of plastic in large quantities. I myself despise happy meal toys for the needless waste.