I’m having 20TB HDD on my desk and i still need at least 2TB iCloud storage.
I don't know if that is simply a statement or if you want help??? If the latter, identify the splits of what is eating up so much data. Apple provides a handy graphical bar to show you the data hogs. Click the "Manage" button by that bar to break it out into even more detail... by app. Click the bigger hogs in that list and it will give you a little description of suggestions to free up iCloud space. Act on some of those suggestions.
And note: I run a robust business and use iCloud too- the free 5GB portion. I also use some free cloud with Dropbox and sometimes Microsoft and Google (client preferences). For a quick file transfer From one Mac to anther, iCloud Drive can be handy (albeit very slow, though so is the other Cloud options).
Again, I'm not anti-cloud or anti-iCloud. My gripe is simply with- IMO- very high pricing. These prices do not appear to be (App Store) 30% off the top or even (general) 4X% margin. These appear to be cost of the tangible storage multiplied many times (and keep multiplying the longer one remains a user). No wonder they are so enthusiastic about service revenue! Services profit appears to be far beyond any hardware they sell... and is the profit that keeps on giving.