1. The world will fine without Bitcoin, mining doesn't harm environment.
I do accept that there wont be any change even if there is no Bitcoin space, but to have a public ledger is an invention that can be used in every sector especially by the government to have transparency. The idea of Bitcoin is harming the environment is just bullshit as if every other industry is boosting the environment.
2. Most people still using fiat for any transactions, Bitcoin is more used for investment rather than a currency.
That is a general concept but where countries that are under restrictions or in the event government freezes the funds, we can use Bitcoin and that has been done
tl;dr Bitcoin do have less or almost none impact to the world.
Things i mentioned is the impact it created, to overcome restrictions imposed by government or restrictions from one country to another is a huge deal.