> [...] so customers who got screwed need to sue and win individually for the same issue which is favorable for the companies doing the screwing as without the precedent of common law

This is factually false.

> (some) Rental agreements, internet, telco and gym memberships are my favorite infamous examples. They're almost universally regarded as anti-consumer, with tonnes of sketchy clauses, but German lawmakers do nothing to improve that for the consumer.

Any examples here? The fact that contracts like these, if you forgot to cancel them, can only renew for one month is better than anything I've seen anywhere else. Also that you must be able to cancel anything online with the click of a button if the contract was made online. Add that to the fact that any clause is worthless if it includes something a reasonable person wouldn't expect. I don't know many countries that actually enforce this - Germany does all the time.