If he's still here, he'll for sure do something and step in but before proceeding, he'll have to propose and educate everyone on what he must do to see the potential outcome of it.
If he was somehow here, he cannot do anything in and of himself, he created BTC to be run based on the consensus mechanism, all controlled by everyone in the community, so even when he was around, he was never BTC's leader or owner, he was only the creator. BTC has never been in the hands of an individual, not even Satoshi.
but for buying and selling transactions using btc in my opinion it should be postponed for a while, and wait for transaction fees to return to normal.
BTC is a currency, do you stop using the dollar because of inflation or counterfeit problems. BTC is a censorship resistant and permissionless currency, nobody can stop or postponed the network from working, you as a person can decide not to use BTC for now, it is a free market, but nodes would not stop validating TX and miners wouldn't stop confirming TX as well. By the way the mempool is becoming less congested and TX fees are cooling down.