Obviously there were plays from the dotcom era that just were not going to work on the timeframes expected because the rest of the infrastructure also hadn't caught up - not just internet, but shipping in general took a long time to catch up, and Amazon having to basically build their own logistics empire shows that ecommerce just wasn't going to be able to be The Thing at the speed those investments required.

But let's say you invested in the NASDAQ at it's peak during the bubble - late 2010s you're whole, inflation adjusted. Obviously, not ideal, but a decade and a half isn't the worst turnaround to make your money back if you just sit. Lots of trades that have gone far, far, far worse.

Smartphones overtook regular cell phones ~2013-2014 as the majority of owned cell phones in the US.

But the NASDAQ started on clear trajectory up and up since 08, several years before smartphones became big.

Smartphones accelerated it, but obviously the internet was going to keep growing and growing and everyone could see where it was heading well before smartphones. A huge amount of the value generated by the internet is on the business side. The amount of productivity from making it basically frictionless to collaborate from anywhere in the world is hard to understate.