I see...
So you can manually change this value, but it is impossible set this value to max and always keep it that way by, for example, constantly overriding the initial value.

Maybe one day some will come up with some sort of an add-on or something, which will prevent this value from being changed back...

As for now, thank you @leocg for your quick explanation and I wish you all well.

There was a chromium switch back in the days like --disk-cache-size="x bytes" it's what he means I suppose. Don't know if it still exists though or if chromium based browsers do have any limitation on the size.