Today fee of bitcoin transactions is increased.
what happended today, I sent 1 BTC into another wallet, and it took 2.5 USD. so high
Of course the fee of bitcoin is increasing because the price of bitcoin is increasing now. Transaction fee was more when bitcoin's price was too high but later, when the price of bitcoin decreased, its fees also reduced. At present the fee has increased due to the price increase.
You can view the bitcoin's transaction fees from the link
https://bitinfocharts.com/comparison/transactionfees-btc-sma7.html#3mSo can you explain why during June 20-24 when
BTC was at 6600-6000, the fee was on average 2.50$ while now, with
BTC over 7500$ the fee is on average 0.70$

Price has nothing to do with the fee, stop saying that...