Many people in this forum consider it unnecessary and useless, if not worse than useless. However, some like it. IMO its main objective is to get you to buy it.
I believe it can be uninstalled via the app itself, but I can’t advise from personal experience.
My general approach with these sorts of utilities is not to install any of them just because they sound good, but only when you have a specific need, and only then when actual unbiased users (such as MR members, not vendor testimonials) appear to have nearly universal praise for them. This is not the case with CleanMyMac.