So both parties are physically/emotionally attracted to each other lets say but they're both submissive, or one has HL and the other LL (/r/deadbedrooms if you want more), or one's into monogomy and the other is polyamorous.

Just a few examples that confirm it's not a 'myth'.

A few anecdotes you mean. Polyamory usually signals a low quality mate, and is tangential to sexual compatibility at best.

Submissive usually means some disorder with the male.

There are tons of disorders that could impact sexual quality of life, but between 2 healthy individuals who are attracted to each other, sexual incompatibility is a myth.

This is some fucked up shit. Submissiveness is a disorder? No it's not.

Sure we can play this game because it's a tautology. My sexual preferences are different from yours? It's a disorder, doesn't count, you aren't healthy.

Having experienced this personally, no, it isn't.

If I want sex a few times a month and my partner wants sex every day that means I'm not attracted to them? No, it's well established people have differing sex drives and sex drives change with age.