All your argument is based on your ignorance of what investing and compounding means. Not interest rates. Investing in stocks, bonds and assets. Nobody ever has implied that you can build wealth by saving accounts.
There are no savings accounts with interest comparable to stocks. If that was so nobody would invest in stocks because one has big risk and the other zero. You are very financially illiterate and I don't mean it as an insult. Sadly these things should be taught at schools. Also, there are currently no 5% saving rates in any of the big currencies.
It literally doesn't matter if there are savings accounts with 5% interest. The example was illustrative and focused on the percentage, not the vehicle through which it was earned. You're being pedantic to the point of distraction here and not adding any value to the subject at hand.
Compound interest is compound interest. 5% or 7% or 11% matters, where that comes from doesn't.