@cimol Valid argument about increments. There are two very different play styles to play by 1 with increment, and one without. Without increment, flagging is much more of a tool.
I'll give you an example. Suppose we are playing a game of chess you, and I. It's a 5/0 game vs 5/2 game.
The same position is in the board in both games. I hardly used any of my time I got like 4 minutes left.
You used much of your time, and have like 30 seconds left.
It's a fairly equal position.
We reach a position where I can make a dubious sacrifice but one you must calculate on to avoid some serious tactical problems. My objective is to flag you with this sacrifice.
5 moves later, and you are down to 5 seconds out of the woods, and I'm down a piece, but you have 5 seconds on the clock, but I still got over 4 minutes.
Welp, I guess I probably won't be able to flag you now you can make dummy moves with that increment... if we play increment, and you will not run out of time and eventually win... or your clock runs out since you are a slowpoke I win.
Been on both sides of situations like this. It's just a different strategy that works depending on if there is an incriment or not.