Obviously you don't mean NVIDIA, because 80% margins on matrix multiplication will last foreverrrrr.
It won't last forever.The question will always be: Are we in the 1995 or the 2000 of the dotcom era?
By 1995, Cisco's stock had already increased 6x since the start of 1993. If you bought at 1995, you'd 10x by its peak. Even after the bust, Cisco's stock was still 50% higher than it was in 1995.
The problem with Nvidia's stock isn't demand. The problem is that Nvidia makes something so good and so valuable that the US government has decided to nationalize them by dictating who they can or can't sell to. If Nvidia is freely able to sell to any country they want, their sales and margins would be much higher right now. The demand is that great.