On the other hand you could say genres like future house are harder to make well and stand out, due to how easy it is to make something half decent with basic presets. Don't get me wrong, I think future house is very easy for people to make, but have mad respect for artists that stick at that sound but keep evolving it and keeping it fresh. People like Tchami who always seems to be one step ahead, some of his tracks may be deemed "easy" or "simple" on the whole but it can't be easy to keep evolving a style like he does.
Personally I think tropical house is one of the easiest, as it usually comprises of simple drum loops and one key melody, but again it can be hard to do very well.
From personal experience Future Bass can be very difficult. Vocal chops take a lot of time to get right and with the over-saturation of future bass right now, it is hard to keep your sound standing out. Me and my duo partner have tried to do this with orchestral elements, but I find that by far the hardest part of producing. It's not really a genre but trying to incorporate "real" sounds and instruments into electronic sounds can be very hard. But when done right has ridiculous results.
Easiest genres are simply those that have less elements, therefore the mix is easier and you can just rape a few presets / loops.
E.g 'future house' / Future bass / whatever the fuck people call it - can literally slam a drum groove and future bass preset patch in there and call it a day. And believe me I have seen / heard plenty of that going on. Mixing is easy due to the minimal amount of elements in the mix. Anybody can chuck in some drum loops and load up a bass preset.
Harder stuff is the stuff which have a lot of elements and layers / soundscapes. Take Progressive house (actual progressive house not 'EDM') or trance for example. Lots of layers, lots of soundscapes, lots of things to try fit in the mix, plus the actual melodic content you need to write - not just a few note bassline on a tube bass patch. Creating different soundscapes and ambiances within your track and then fitting them all together is the difficult part - and trying not to make it boring.
compare something timeless like some old Chicane stuff or even newer stuff like pryda / deadmau5 to some of this new 'deep house' (which isn't deep house) / trap / future bass etc and the complexity isn't comparable.
But no one gives a fuck how hard something is to make lol. Some of the most timeless records have sampled a disco track and slapped a drum groove under it. Sometimes the most simple of tracks are the best. Personally I have one Alias for more proggy / techno related stuff and another for simple house stuff - 909 drum grooves and basslines, nice and stripped back - usually when I'm at a wall with the more complex things I will mess around with that stuff.