If we compare the price of bitcoin and the next most popular altcoin (which i consider ETH, based on coinmarketcap) they have a huge difference, $640 with $12 and saying this means that if bitcoin goes 6k it is x10, and eth to go to 600 is 4900%.
Timeframe probably minimum 1 decade.
due to the fact that ETH has 85 mil coins already (maybe about 90 mil limit), bitcoin about 16 mil (21 limit), eth price at equal market cap is about $122 currently, so $12/eth means ethereum has 10% of bitcoins market cap, so if btc would be at $6000, eth would have to be at $1130 to be at market cap parity and at $113 for 10% of market cap.
I definitely consider $6000 possible for btc and $113-225/eth (10-20% of market cap) in 10 years.
It is also possible that btc or eth developers make a serious mistake and the situation can flip, although it is less likely.
Everytime the price of a coin is going to up and being stable a "hack" happens always like with the bitcoin at the halving period when bitfinex was hacked. I'm thinking too that in minimum a decade from now the price can reach that target.