Usa is a common law based system where court judgements also serve as precedent rulings. It is more or less regarded as law even though its not passed by parliament/legislature.

There is another system, civil law based systems where law is passed by parliament and doesn't depend on any court precedents or court interpretation.

Might as well have just courts and call it as adaptive system instead of acknowledging that is isn't a good enough system. Europe has done better in this regard. Checks and balances hardly works in usa. Plenty of news on subverting various constitutional guarantees is example that it failed to work.

Proper democracy needs properly functioning non-lazy legislature. Making vague laws and calling it a day and leaving it for judges and lawyers to interpret based on whichever way the wind is blowing isn't democracy.

Legislature can also work 40 hours a week. Things can be more functional rather than dysfunctional. Active democracy and direct democracy where people can veto laws if necessary, in case representatives collude to pass draconian laws, would be the best kind of democracy. Only that can prevent erosion of rights.