You provide no fee statistic to back up that its higher cost than credit cards or paypal.
Why did Steam stop accepting BTC? Because of the unpredictable fees. People would make purchases with out of date wallet software that would include an insufficient fee for the transaction to confirm. Then when their purchase didn't go through, they would contact Steam support. The costs incurred by this were greater than the profit they were making from BTC sales.
Merchant adoption day of segwit upgrade (april 27th 2017)
Now, I can see that I am wasting my time replying to you, since you are clearly clueless. SW was not locked in or activated until August.