Yeah it's true having bigger capital will make you to earn high return, you still need to pay attention with the percentage.
You need to overtake inflation in your country, I'm not sure which country you live, but in my country the inflation rate stated by central banks is 6%, but the reality the inflation rate is around 10%-15%.
So, earning 5% is still not enough, in the long run your money will lose the value.
What you said makes sense but look at OP's example, if your capital is 100k and your profit is only 5% but you can already make 10x more profit than someone with 1k capital $ with 50% profit. That means you still make more money, are richer, and I don't think inflation will affect you if you spend like someone with $1k.
That's why rich people who own millions of dollars will choose investments that bring small profits but have high safety like gold and they are still richer than bitcoin investors with capital small.