Number of active overclockers is constantly dropping. Most active are those who are in the game for a long time or those who work for some manufacturers or are reviewers and have easier access to hardware. In rankings like hwbot most new overclockers quit really quick. On the top of the ranking ( count like top 100-150 ) are the same people for long years.
Gamers don't need any special hardware and they usually don't want to have problems with settings while many still want to OC some ... because they think it will help them in games.
Market is set to the highest profit so they don't care about overclockers but about gamers. For them are all these e-sports events and huge competitions. So hardware is also designed to satisfy gamers - read to deliver flashy hardware which can easily OC , best if 1-2 clicks and you have 4.5GHz.
Other thing is that hardware is becoming more idiot-proof. You have to really try to break something. Memory auto or XMP = in 95%+ cases works fine. CPU auto or manual up to 4.5GHz = 95% will work fine ( board will set required voltages ). Graphics cards the same. In graphics cards they even moved further as you can't burn any new card because of overvoltage or overclocking in general ( forced OCP/OVP ). In most cases you can't even remove cooling without losing warranty.
It also works against extreme overclockers who are forced to use only dedicated hardware or their results will be much lower ( read that hardware or BIOS is missing some options ). Like most of the results on Z170 are made on ASRock OCF now , most just after Z170 premiere were made on ASUS Gene/Hero. So maybe 90% higher ranked results on Z170 are made on 3-4 motherboards ... while we have 100+ on the market and most have similar specs.
It looks like manufacturers are controlling how high can you overclock everything. It's actually related to RMA rate of their products which can't be too high. Premium price as always includes risk of hardware fail due to overclocking.
I guess we went far from the main topic
... sorry for that, I'm just not happy to see how overclocking in changing.