I'll give an example to highlight the point:
Imagine there was an investment that returned 1% each day. But every single day, in the evening, they gave you all your money back. Each night, you had to decide whether or not you wanted to invest the following day.
You start off with $100. That night, they give you $101. You decide to re-invest and give them $101 for the next day. At the end of the next day, they hand you $102.01. This continues for 1 week, after which you have $107.21. They return this money to you. This has been great, you've been having an average rate of return of 1% per day. This night however, you decide you don't want to reinvest. You do this 1 week. So after 14 days, you still have $107.21. This means your average return over 14 days, more or less, dropped from 1% per day to 0.5% per day, solely because you stopped investing. This makes sense, if you don't invest your money, you won't make any returns, and your average rate of return decreases as time passes.
In the case of LC, it's similar to the above example, the only difference being that each night they give you back ~0.07% as opposed to 100%. If you don't re-invest what they give back to your, your average rate of return will decrease. However, the rate of return for the money that you still have invested, will remain the same.
Imagine there was an investment that returned 1% each day. But every single day, in the evening, they gave you all your money back. Each night, you had to decide whether or not you wanted to invest the following day.
You start off with $100. That night, they give you $101. You decide to re-invest and give them $101 for the next day. At the end of the next day, they hand you $102.01. This continues for 1 week, after which you have $107.21. They return this money to you. This has been great, you've been having an average rate of return of 1% per day. This night however, you decide you don't want to reinvest. You do this 1 week. So after 14 days, you still have $107.21. This means your average return over 14 days, more or less, dropped from 1% per day to 0.5% per day, solely because you stopped investing. This makes sense, if you don't invest your money, you won't make any returns, and your average rate of return decreases as time passes.
In the case of LC, it's similar to the above example, the only difference being that each night they give you back ~0.07% as opposed to 100%. If you don't re-invest what they give back to your, your average rate of return will decrease. However, the rate of return for the money that you still have invested, will remain the same.