In your magic example you seem to be arguing that which kind of deck you pick is not part of your skill, which is of course totally incorrect. Picking "fun" decks over "obvious/OP" decks means you're worse at winning games. Or at least that you generally play with a handicap, which is easy to account for in elo.
To your coin-flip example, if you model a league in excel you'll find that elo actually results in a rank distribution very consistent with what your intuition would expect (given enough players and enough matches, of course).
> To your coin-flip example, if you model a league in excel you'll find that elo actually results in a rank distribution very consistent with what your intuition would expect (given enough players and enough matches, of course).
This is incorrect. If you simulate Elo with a coin-flip, you'll get something that looks like this (11 players, 1000 matches): https://imgur.com/9O82pRj -- I think this will tend to a geometric distribution (not sure what the p is though, probably depends on the constants).
To your coin-flip example, if you model a league in excel you'll find that elo actually results in a rank distribution very consistent with what your intuition would expect (given enough players and enough matches, of course).