Freelancers in Germany don’t pay higher taxes. They pay income tax like every employee. They loose the employers share of social security and pension, but the remedy for that is to adjust rates - you also loose paid holidays, sick leave and all of the other employment benefits, but same - reflect that in your rates. You can opt into pension if you choose to, some freelancers are even required to (see 1). If you don’t opt into pension, you don’t need to pay into the pension fund. Unemployment insurance is similar: you can opt into it when you start freelancing, but if you don’t, you don’t need to pay for it.

(Source: I am for social security and tax purposes a freelancer)

(1) https://www.fuer-gruender.de/wissen/existenzgruendung-planen...