Why is the BTC/EUR pair more expensive?

I’ve noticed something a couple of days ago, but maybe it’s already been like this for a while and common knowledge, so excuse my stupid question. The BTC/EUR trading pair on Binance tends to be between 250 and 350€ per BTC more expensive than the USDT/BUSD/other fiat pairs on Binance and also all other pairs on other exchanges. I understand that there are differences between trading pairs and arbitrageurs make profit of that, with the result that ultimately prices go to an equilibrium. This does not happen with the BTC/EUR pair on Binance and I wonder if there’s a reason for it. You can easily see it in the markets comparison on CoinmarketCap or the markets overview on Binance itself, if you set your standard fiat currency to Euro.

P.s.: I checked and this is also the case for ETH and probably all cryptos. It’s a ~0.7 to 0.8% “premium” if you wanna trade in EUR directly.