The market is definitely efficient. Try to find arbitrage opportunities (which is what actual market inefficiency is); they disappear in milliseconds.

What you're saying is that it's not infallible as far as predictive power is concerned, which is true. But every current bit of knowledge is definitely priced in.

Markets are efficient over long time spans but in short term are definitely inefficient. You can just look at volatility during earnings and lack of liquidity in small caps.