But that's ridiculous - many many years of continual study and professional development are required to be a developer - with lots of it happening of the job in the developer's education and personal time.

About a week of on the job training is required to go from an entry level cleaner to an experienced cleaner.

Not only that, but in Germany many companies will not hire you, if you don't have a degree. So you must also spend a lot of time (3-5 years) and money to get a Bachelor/Master degree.

Money? What money? AFAIK degree programs in German public universities are nearly free.

In public universities yes, but not in private universities. You will also have other expenses as well when you study (rent an appartment, food etc.)

Don't do that then?

It is ridiculous if you associate pay with degree/profession, but it is not if you associate pay with the offer and demand equilibrium. If there are no revenues to be taken or no demands for a professional, there’s no reason to pay them more. Degree does mean someone deserves to make more.

Maybe. All i know is i would much rather be a computer programmer than a cleaner, even if being a cleaner paid more.

Depending on who you ask, income inequality and returns to education/skill are anywhere from closely related to the same fact.

The managerial class in Germany earns much more than normal workers. The point here isn't that Germany somehow successfully combated inequality, just that it doesn't value software engineers as much as the US or even the UK does.

Another way of framing this is that this is completely false, a house cleaner in Germany doesn't make anywhere close to 2400€/month after taxes. Unless he works all day and night including weekends without declaring any of it maybe, and even then that's a stretch.