What countries did you check. None?
No it's not all about growth. You've already had some.
I know a bit of detail about a couple of them but I'm not going to argue with someone who sounds determined to be an obdurate simpleton.
I checked France and Germany. I already told you that. I quoted something of a rate, iirc 12% gets taxed at a variable rate, or summat.
Get off your googling bottom and find out - here's Netherlands....
https://taxsummaries.pwc.com/Netherlands/Individual/Income-determination
"..... Capital Gains Not taxed, except as...." boxes I can't be bothered to look at but obviously it's complex, not all as normal income.
"Interest income that does not qualify as income from substantial interest
(see below) is taxed in accordance with the rules on the taxation of dividend income, i.e. taxable in box 3. The actual interest income received is thus not taxable."
An "All got to be the same %" assertion is as pitiable as that a 12 year old would make.
"No, sonny, there are lots of things different countries treat differently for a variety of reasons, go look it up for homework". I don't need to have details of all of them to know the 12 year old is talking crap, however many times he repeats it.