The important sentence in the article is:

" I own a few companies which means I'd be hit by the German exit tax. "

We don't know how many companies does he own.

We can look into exit tax rate, in different countries:

Germany: effective tax rate of up to roughly 28.5%

Japan: CGT rate is 20.315%

Israel: Standard CGT rate is 25%

Austria: Standard CGT rate is 27.5%

https://en.wikipedia.org/wiki/Exit_tax

It's very good you mention Switzerland, as the contemporary German exit tax legislation traces back to the scandal with Helmut Horten, a department-store magnate who moved to Switzerland in 1968, sold his business stake and paid virtually no tax. The event prompted enactment of the Foreign Tax Act (Außensteuergesetz) in 1972, whose exit-tax provision (§ 6 AStG) is nicknamed lex Horten.

   Change or add company address
   "Änderung des Rechtsdomizils oder einer zusätzlichen Adresse"
   30 CHF

   Change CEO
   "Eintragung, Änderung oder Löschung von Personenangaben oder der Funktion einer Person"
   20 CHF

   Changing company suffix
   "Umwandlung in eine juristische Person"
   420 CHF

   Deletion (from the registry) due to leaving the country
   "Löschung infolge Wegzugs ins Ausland"
   210 CHF

Switzerland uses an exit tax I don't quite understand. The companies "hidden reserves" are valued and taxed about at about 17%. Those include the "goodwill" you have generated over the years, which is similar, but not the same, as the market value.

How about we switch - you move to Germany and get barred from leaving the country.

I look forward to your blog post.

Those only apply if you renounce your citizenship, not if you simply change your country of residence. However, unlike Germany, the US taxes its citizens regardless of their country of residence so renouncing your citizenship and paying that exit tax is the only way to stop being responsible for paying US taxes.

They wanted him to pay almost six years worth of his normal post-tax income. Did you have to pay six years worth of income? It took him a lot of work to get it down to 'only' 18.7k€.

This ranks right up there with the author who wrote a children's book about a village where they had to turn over 102% of the potatoes they grew. https://en.wikipedia.org/wiki/Pomperipossa_in_Monismania

It's idiotic. You spend your life paying taxes that go to fund programs that decrease your rights and inflate away your savings and then when you want to leave they request that you then give them another cut just because you were born in the country and provided value to the world.