If making money in the stock market is easy, even though I have enough experience in it, why have I not been able to achieve that level?

Most think it fast and easy it isn’t. Iv been trading for 50 plus years .The secret is buying solid company’s when the market is down than hold enjoy the dividend an stay informed.

Easy? No. Possible? Yes. Over time. 

There's something wrong with your strategy. I'm guessing you are buying overpriced junk. 

It's only easy sometimes. While the economy is growing and we have a bull market it is a lot easier to pick stocks that go up. If you can't make money in today's market you need to get out because things will get much harder in the future.

If you have the experience in it, but havent been able to make much money on it, its time to rethink your strategies. Go different routes. Theres all kinds of price levels when it comes to stocks.

If making money in the stock market was easy, everyone would be doing it.

Making money in the stock market on short term investments is not investing, it is gambling.  For every person who wins there is a person who loses.