I cleaned my MacBook with CleanMyMac 3 and it fell off - what should I do?

Question

macOS

After cleaning, I rebooted the macbook and it has not exited the download for half an hour (previously it loaded 3-5 seconds), while it lags - every 15 seconds the mouse is shown, the loader is shown at the same frequency, but does not disappear later, but simply superimposed on the old images .
Only about 30%
loaded. I cleaned a lot of things, including language localization, some modules from extensions, but can the program remove something that will affect further work?

Answer 1

SMM - slag, with competent marketing.
reinstall the system. will be faster than grazing on the toaster and solving the problem.

Answer 2

but how can a program remove something that will affect further work?

Quite