Oh, I get to do all the work and you get to dismiss it with "Metagaming bad?" What a great deal for me!
Yes, you get to back up your claim that all metagaming is the DM's fault. Not interested in doing so? That's funny.
Instead, please go ahead and make a list of all instances of "metagaming" that bother you and we can then discuss how the DM sets up these opportunities to happen.
All metagaming bothers me. Every time a player makes a decision (any decision) based on game mechanics or out of character knowledge, that's metagaming and it bugs me. Let's see, some examples.
The Book Club. Split party. Group 1 on the far side of town suddenly decides to come running to Group 2's location because Group 2 is in some trouble...despite Group 1 having literally no way of knowing that Group 2 is in trouble. One common cheese excuse, "I borrowed this book from [PC in Group 2], I've decided I should return it."
The Walkaway. Group has a prisoner they've decided to torture for information. So the paladin goes for a walk. An oldie but a goodie that is more about old-school D&D than 5E. But I still play old-school D&D, so it's still a problem that pops up.
The Fire Hose. Low-level group encounters a monster for the
first time and magically knows its vulnerabilities. Party encounters a troll..."Everyone blast it with fire!" Party encounters an ooze..."No one hit it with slashing weapons!" Easily solved by homebrewing and/or reskinning, but it's still metagaming and gives me more work because the players can't be bothered to roleplay instead of metagame.
The Omniscient Tactician. Typically a wargamer, the player who looks all around the map and makes decisions based on details on the map their PC couldn't know. Enemies behind doors, around corners, etc. Perfect AoE placement into other rooms when their character doesn't know there's even enemies in the other room. Etc.
The Spot Healer. Party healer who doesn't heal until someone goes down because "pop up healing" is more efficient. Also PCs not bothering to do anything about another PC making death saves until they get two fails.
The Wow Raider. The player who comes from video games and thinks D&D is like a WoW raid so they read up on all the monsters, read the module, etc so they can be as efficient as possible. Either never use anything written down by anyone ever or boot them. Infinitely easier to boot them. Also the DM's notes reader. Pure boot them.
The Skill Dogpile. Someone makes a roll and fails so the rest of the group (or anyone proficient with that skill) decide, magically, to saunter over and make the same roll, just in case.
The "Fun" Thief. The rogue finds something without telling the group. If it's a trap, the other PCs get to walk right into it or metagame. If it's treasure, the other players get to pretend they don't know. Either way, this builds resentment at the table. But it's the rogue intentionally being a jerk by centering metagaming. Best solution is to boot them.
The Second Guesser. The player who knows the DM really well so decides to use that knowledge to their advantage. "Tony really digs traps and puzzles and riddles, so I'll go read up on traps and puzzles and riddles."
The Infinite Resters. The group that insists on going nova every fight and taking a long rest after every fight. Easy solution, waves of enemies.
Not an exhaustive list, obviously.
Now, some of those have solutions included, some don't. I'm more interested in you explaining how all of these (and all other instances of metagaming) are the DM's fault and not the players.