Is it really necessary that CCleaner open by itself?

Creator must to learn to make friends and stop being a loser

CCleaner does not ‘open’ by itself.

If you are using Smart Cleaning, or have it set to ‘Keep CCleamer update Automatically’ then they will run as a background task at startup, and Windows will put a CCleaner icon in the System Tray (near the time/date).
If you turn those two off the yoy won’t get that icon either.

CCleaner will also launch a couple of non-optional background tasks at startup, but Windows doesn’t show an icon for those.

PS. Don’t you think that it might be a good idea to learn about how something works, and why it does what it does, before making sarcastic comments about it ?