I understand how distributing bond etfs could work, you get part of the coupons when the etf distributes profits, which compensates somewhat for the price changes of the etf. Interest rates would affect the price of the etf but that would be partly compensated by the distribution.

But how does this work on accumulating etfs? If the profits are always reinvested in the fund, shouldn't the price of the fund always go up? Assuming all/most bonds dont default, interest rates would affect the price but that would be compensated by the reinvested profits?

I am missing something here, dont see the point of a bond etf if the price can change so much.