The answer is pretty obvious. Your campaigns cost too much for the revenue they are bring in.
It might seem like a cop-out answer, but it contains useful insight.
Making Google Ads work, is all about controlling cost.
And that starts by not wasting any money.
You might not be aware of it, but Google has optimized its own system to extract as much profit as possible from unaware advertisers.
These are things like default options, new features, and more automation that instantly put you on the track towards unprofitability.
Like this one: