But you also have to look at it over the term.
If you pay 30k€ more over 30 years, that is just 83,- per month for interest rate security over 30 years. So you can almost see it as an "affordability insurance," if you will.
Personally, I see it this way:
Today, you know (less than ever!) how everything will develop. In the past, the world (technologically and socially) simply moved much slower. Today, it looks extremely different. One technological revolution chases the next, and never have so many professions and fields of activity been overturned as today.
I gladly invest a few euros a month in interest rate security, even if I might not need it.
My life has changed due to illness from a powerfully healthy person to a severely disabled person with significant everyday limitations; such things shape your future thinking as well. A banal tick bite, nothing more, was the cause. "It can happen that fast" is the message I want to convey with that. But something like that should not be able to influence my personal living future, at least as far as one can influence it.
Instead of a shorter interest rate security, we chose a flexible financing option. That means in our case, we can either pay off slowly and securely, but also prepay at any time if the account balance is good. That, combined with a repayment corridor of 3 percent, which can be changed monthly, provides enough flexibility and security for our ideas.