My opinion:
Satoshi Nakamoto is one person and will come back with the improved Bitcoin and with another pseudonym. He will not try to advertise or sell the new concept because he knows that the Bitcoin and crypto community will use it as it will be good.
what about those altcoins and tokens that we saw ? arent they the new bitcoins that you are talkin about ? i think they are because btc was the first crypto coin that is introduced and we can say that it was a test to see if it will become a succesor but it did and after that , altcoin and tokens suddenly appeared but those devs are i think not satoshi or related to him . they only get some idea on the concept of the orginal bitcoin and they make a little change on thier own coin .
All coins use the same technology, blockchain. But the blockchain as we know it today can't solve the above mentioned - speed, scalability - issues. The next developed decentralized coin would use a different technology without these issues.
Bitcoin worked without advertising, selling. The new concept would make it the same way and would not work 10 years ago, as for the new concept a crypto community is needed, who will build a great stable network, what would be important for the new concept.
The price today is not important, if the concept is good. The concept will make the future's price.