It could be a simple stress fracture. Car bodies are not 100% rigid and every car body suffers some body flex while driving. Maybe you just happened to get one of those with a tight fitting windshield and age/miles caused the glass to give up.
When I worked for Subaru I saw 4 or 5 Subarus that suffered stress fractured windshields and 2 of those were on near new cars; 200 miles or less.
Any aftermarket glass is fine if it has the DOT stamp on it. Keep in mind that Subaru does not even manufacture their own glass. They have it made for them and it’s quite likely made by the same company that provides glass to the neighborhood glass shop.
The only difference is the stencil used.