Agreed. I'm fine playing with high elo players, but the constant diamond, plats, and occasional golds versus 3 x silvers, me, and maybe a plat just isn't a fair matchup. Supposedly Riot added/modified "splash" this season to make some of the ranked MMR count in normals, but this is just crazy right now. Almost every match I'm in has an op.gg MMR calculation of 200-500 differential. That's like 1 to 2 tiers higher. Sometimes we win, but I'm alright having one match at the gold level or so.
The issue is right now many of the higher elo players aren't playing ranked because the game's just not settled enough yet. The preseason changes are still a bit much to take in, so people are practicing in normals. Many high elo players' normal MMR is considerably lower than their ranked MMR, so the system "thinks" it's a roughly fair match.
Obviously, it needs some major work. It's a poor experience when there's that large of a gap on a consistent basis. It'll go away once the meta settles and the players go back to ranked, or after x games are players in normals, but it's not a fun experience until then. Riot has not acknowledged this problem and put any kind of real effort in to address it yet. They probably don't want to touch something that will eventually fix itself...despite the community's need for them to do so.