The financial markets are close to being efficient...
Sounds like you're arguing the semi-strong efficient markets hypothesis. So far I'm nodding in agreement.
...because there are smart people who are paid well to exploit inefficiencies.
Ehhhh...not really.
Markets are efficient because, otherwise, arbitrage opportunities would exist that investors would trade away. This presence of institutional bankers with market-making capabilities simply means that the process is accelerated because of the trade volumes they can sustain on transactions where retail investors' profits would otherwise be consumed by transaction costs. This is a volume- and specialization-linked advantage, not necessarily an intellectual one.
Also, this line of reasoning appears to be inconsistent with your efficient market values. If you believe that markets are efficient, then you should be advocating for investing in a well-diversified ETF. The article you cite doesn't factor in serial correlation of returns captured by managers outperforming the market, which is problematic, because mean reversion to returns approximating a random walk plus drift is what the literature observes. (See Malkiel, Fama).
