True, no one is in the position to judge the "right or wrong" way of teaching a child, but whatever that you are doing to a child WILL have a LIFE-LONG impact on that child. We all want our child to have a happy childhood. Who doesn't? But if there is one thing in the whole world that parents want more than "the happy childhood", it must be "A happy life" for their children. Simply put, What we truly want is: A happy childhood that prepares them for a happy and desirable life.
Your formula here is: learning early (in a happy way) will lead to a head start, which will in turn lead to a better school, then better job, better salary and better life. First of all, let us not focus on head start. In any competition, the winner is always determined at the finishing line, not the starting point. And even if we could place our child ahead on the starting point, we cannot run the race for him. He needs to be mentally and physically ready and run the race himself. Better life and better jobs needed to be pursuit after by themselves. Motivation, determination are all part of the "early learning" that cannot be learned from just books and flash cards.
Another critical point that I must raise here is the definition of "early learning". What is "early learning"? "Reading early" alone is not "learning early"? I am 100% pro reading. I have a library of children's book at home, and I read to my kids every night. But knowing the information in an encyclopedia does not necessary mean you are wiser. And why is learn-through-play, hand-on learning and manipulative important? When you do flash cards, say, flash a child 10 dots on a card or the word "ten" on a card. The child might realize that 10 is more than 1. But will the child realize that 10 is longer than 1, or that 10 is heavier than 1? But the child who lines up toy cars at home might realize that. When you flash a photo of a "Stingray", how much other details could you force feed him? But a child who goes to, say Ocean Park, will have a photographic image of how the stingray glide in the water and how its habitat looks like and how it is in relation to all other aquatic animals. That is their own LIFE experience. It's like a film that they need to record in their mind map. you wouldn't want them to record in their mind a room with mom with flashcards after flashcards. Please don't deprive them their rights of experiencing life and viewing the world with their own eyes.
We want children to have a mind of their own. We want them to observe and draw their own conclusions. We want them to build their critical thinking, be creative and be problem solvers. You need to have experience in life. If we are constantly feeding them information, how do we expect them to be leaders and not to rely on us in the future?
Every little information that we provide them, we take away one chance for them to discover on their own. I understand that we must provide photos and explain at times. We can't bring them to the jungle or to all the world's monuments. But before you flash them the next time, think how necessary it is to flash that card.
p.s. Although I mentioned competition and race here, as a Montessori teacher, I believe that children learn more in collaboration than competition.