In the UK, if you buy an accumulating ETF, then the dividends that your share of the ETF receives are considered to be income to you, even though it is automatically reinvested and not directly paid out to you. And thus you have to pay income tax on the dividends that you never see, which is more annoying to calculate than if you just pay income tax on dividends that are directly paid out to you.

And when you finally come to sell, your capital gain calculation is complicated because you now have to account for all these small purchases that you never directly made.