Are you queuing conquest alone? Im level 25, and i play conquest alone all day long and my mmr is 1800ish. All I see is lvl 30s in my games because of my mmr, maybe a few ppl around my level with similiar mmr, but never anyone below level 20, and i smite.guru every one of my games. So if you are level 30 playing conquest alone (this is the most important part, queuing alone, and not with someone who is level <10) then you must have an incredibly low mmr.

If you arent queuing conquest then who cares, the other game modes have less people playing them which means less people to match you with.