Trend following was called dead many time in last decades. Always came back from the dead with vengeance dwarfing all other types of trading. 2 years is nothing for long term trend following.
Buy and hold is the real trend following. If you buy and hold BRK for 30 years, you would have outperformed SPY by a wide margin. But it is hard for a hedge fund to justify charging 2/20 for buy and hold BRKA.
for example, take the E-mini future, RTH session, daily chart I wonder about the bad trend following results in 2017, because there was a nice uptrend in place (green colored EMA) but for 2018 I certainly would switch to mean reversion, that large correction put the index into TR mode
How do you define the word strategy, is it simply the entry criteria and execution or does it entail all parts of a system such as exit strategies, position sizing, risk management and money management? Simply saying that both trend following and mean reversion strategies got more difficult is very generalizing. I know of many mean reversion strategies that have killed it since late february.