Which "Stage" is the most important: Endgame, Middle game or opening?

Endgame, Middle game or opening?

The endgame.
The opening is to prepare the middle game.
The middle game is to prepare the endgame.

Most games should end in the middlegame. So, the middlegame is the most important. You don't need to know how to play an endgame if you can win in the middlegame!

Almost no games between strong players end in the opening.
Few games between strong players end in the middle game.
Most games among strong players end in the endgame.

Some other GM said to study the middlegame as a priority.

Correct.

Conceptually, the endgame is the most important.

You cannot play the middle-game properly unless you know what a winning endgame LOOKS like.

You cannot play the opening properly*** unless you know what a good middle-game LOOKS like.

*** except by brute force memorization, which will leave you up the proverbial creek without the proverbial paddle if your opponent hasn't memorized the same opening lines as you.

If I've specialized in any of the phases, then I would have to call myself a middle-game specialist.

... but I studied the endgame before attempting to get good at middle-games!

They are all equally important.

The middlegame, because in the opening, there aren't any "strong players" And, in the endgame, the endgame is " dependent" on the middlegame because of the certain endgame positions 

Opening because it's the beginning of endgame.

Those are just empty words.

Below 2000 rating, 10% of games are decided in the endgame, 5% in the opening, 85% in the middlegame.

I would say 60% middlegame and 30% endgames and 10% opening ( in terms of importance)

But all of them are important. It's pointless to say that endgame is the most important and blah blah blah. All of them are dependent on each other. Without knowing which endgame is winning, you can't create the late middlegame planning. Without knowing what kind of middlegame you like, you can't choose your opening and so on.

Yes. True. But winning endgames with a significant material advantage are different from regular endgames.

chess is like a road trip.

no preparation, no maintenance, no schedule and the station wagon may never leave the drive way. that's the opening. no road trip.

a flat tire, an engine knock, a busted radiator hose, that's position, tactics, and bad piece development in the middle game. no road trip.

you can drive 300 miles and never reach your destination cause you are lost and driving around in circles. that is the end game. no road trip.

everything about the journey is important.

Its obvious the opening! Once you learn the opening you reach middlegame phase!! If you want to learn to think only you must study the endgame first!!