Descriptive Notation Sucks
If I move a Knight to a certain square, and my opponent moves a Knight to that same square, Algebraic it's the same, like 24.Nf5 or 24...Nf5.
In descriptive, it's N-KB5 for White, but N-KB4 for Black.
Secondly, Descriptive has too many clarification requirements. In Algebraic, except in the rare case where a promotion occurs, it's only Knights and Rooks. Rad1 vs Rfd1 or Nbd7 vs Nfd7, for example.
With Descriptive, using the stupid PxP (no square indicated), you have PxP if only 1 pawn capture is legal, then you have PxBP if multiple pawns can be taken, one of which on a Bishop file, one not on a Bishop file, then you have PxKBP if the 2 pawns that can be taken are on the 2 Bishop Files. And now, what about if Black has doubled pawns on KB2 and KB3, White has pawns on KN5 and K6. Now White can take either pawn, both pawns are on the same file. How do you notate that?
Also, for clarification requirements in Algebraic, both must be able to reach the same square. In descriptive, you need clarifications on move 1, like P-B4 and N-B3 aren't enough, you need P-QB4 or N-KB3.
Also, with Algebraic, if you've played 20 tournament games, and still need the letters and numbers on the side of the board to notate, then clearly you need to spend way too much time thinking about notation, can't focus on the game, and never will be any good anyway!
You ought to know the algebraic board by heart after 20 games of notating moves in Algebraic. I'm not looking at a board right now, and I can tell you off the top of my head, d4 is a dark square, g6 is a light square, b5 is a light square, c7 is a dark square, etc.
Algebraic is so much easier and far better than Descriptive
One can have multiple queens, and possibly multiple bishops of the same color. Just a quick example:
Don't you wish? >:[