Question: why castle?

I see many people castle but I often feel like castling is a disadvantage, what do you guys think? Oftenly a castled king is easier to checkmate with a kiss of death, but maybe I havent gotten to a high enough rating yet to face opponents who know how to stop such checkmates efficiently? inform me please why castling is considered an advantage

Ah that makes sense. Oftenly my opponents dont have the knight on f6, which makes me able to perform kiss of death with bischop and the queen at h8. I guess thats a weakness not everyone thinks about

It is also protection for your king. In the upper levels many people castle opposite sides and start out a full on first to get a checkmate on the opposite side war. For now tho just castle king side for protection and activate your pieces.

At higher ratings players are better at defending and also attacking an uncastled king. You may find it works for you against similar opponents, but will hold back your improvement. Experienced players will develop their pieces quickly and trade off centre pawns to open up the game if they see you are not castling or unable to castle. A central and exposed king is a magnet for many tactics.

Always be carefuly you don't castle into a knight fork though!

Castling is a part of many openings, but not every game is played with one or both players castling.

Rarely, a player can castle in the endgame as part of a mating net.

Weaponized Long Castle

If you don't castle, your opponent will have a straightforward plan of opening the center and attacking your king. If you can block the center completely you may be able to play without castling and have your king safe, but then you need to do something else to get your rooks into play.

Apart from connecting rooks, in most (not all) cases, king is more exposed in the center. In closed positions king might be fine at the center, but if center pawns start to get exchanged, rooks might be located in line with the still uncastled king, minor pieces might start attacking the king etc.  The side which didn't castle might regret it pretty soon. 

For instance, I have covered the opening phase in this article, and in most cases shown there, the losing side lost very fast because of the time wasting moves and the uncastled exposed king. 

https://www.chess.com/blog/nklristic/surviving-the-opening-first-steps-to-chess-improvement

Stronger players have better sense when it is perfectly fine not to castle but it is generally more tricky to play that way. Of course, sometimes a pawn storm migh happen on one side, and you might want to avoid to castle into your opponents attack, but those are some pretty specific examples.