That's not true. The Moon is the gateway to the planets. Elon should be building a base on the Moon instead of going straight for Mars.In fact, our rocket technology hasn’t changed in any fundamental way since The Nazis first used them to drop on The English.
In fact, the most recent SLS system from NASA is a step back from The 1960s Saturn V. The SLS uses more fuel per launch with a lower net payload and has a much higher failure rate than its 60-year-old predecessor.
We haven’t been back for a very simple reason. Other than proving we could beat The Soviets, there is no economic or scientific reason for doing so.