Why is there an audible tone to warn off time?

As above

Why not??

? ? Do you know what chess is?

Preferences -> Chess Clock -> Sound when time gets critical -> No

Thanks

It's a legitimate question. It's another thing that lichess does that is not consistent with the generally accepted rules of chess. There are a lot of those things, and I think it makes sense to not be 100% consistent due to the experience being different playing online instead of OTB. Some other things that are also inconsistent:

1) auto-flagging (winning as soon as your opponent runs out of time instead of manually needing to call a flag)
2) auto-draw on repetition (option to enable, otb the draw must be manually claimed)
3) ability to draw on board or whisper variations to observers (both are blatantly note-taking, which is forbidden otb)
4) not stopping your clock manually after a move (it happens automatically when you make a move)
5) touch move (ability to either hover a piece over a square without letting go or actually make the move and inspect it before clicking confirm)

There are others, but when lichess allows something that is not allowed in OTB chess (or vice versa), it is reasonable to at least wonder if the decision is valid.

Well said old chap

Online chess is not OTB chess. In case some of you were confused. :|

What is the point in being the exact same? Variety is what makes one thing better than another. That's why Lichess is the best.

I really hope you guys read my post closely enough to see this line:

"I think it makes sense to not be 100% consistent due to the experience being different playing online instead of OTB."