A key feature of AIM in addition to price appreciation, income and volatility capture is overriding human emotion.
Whilst many will grocery shop in a buy more when cheaper manner, when it comes to the stock market many do the complete opposite. The realities is that can add a further 2% lag factor through having sold when scared, bought when greedy.
8% nominal, deduct perhaps 2% for costs/taxes, another 2% through bad trading, and another 4% for inflation and many investors take on 100% of risk for zero personal reward (they're investing and taking on considerable risk for the benefit of others).
AIM is more likely to have you trade in an appropriate manner of adding when low, reducing when high in practice. Such that your actual gains are more aligned to mathematical rewards - that many tend to lag.
Clive.