chess online

Most puzzles teach you a particular idea to use in a particular type of position. This type of puzzle forces you to find a plan and execute it precisely through careful analysis of both yours and your opponent's moves.

Of course you will never see this situation in a real game. For that matter, you may play chess for a lifetime without ever having the chance to pull off a smothered mate. But every game you play affords opportunities to apply the planning and analysis skills you can practice in a puzzle like this

I agree with you that in composed ("made up") positions, unnecessary pieces should be avoided. But here, part of the clutter is necessary to insure that none of Black's pieces can move and spoil the solution. For instance, if everything from the f, g, and h files were removed, then the bishop on e1 could move.

It's possible that some of the pieces could be removed, but the position as is also has the effect of showing Black's entire army helpless against a single knight. Whether that is worth showing is debatable, but that's probably what was in the composer's mind.

Many solvers here--indeed, probably the majority--would agree with you that this puzzle is unrealistic and not worth the time. I just like to be sure that other points of view are mentioned. Nobody should object to an argument that is conducted respectfully, though unfortunately too many of them descend into heated name-calling.