No they'll become too big to fail and will be rescued by the Americans' govt every time something bad happens

Nah we're all fucked

I think big tech has already begun to decline. Their only remaining stranglehold is on search crawlers, and geriatrics

I'n thinking it could happen over 20-30 yrs, they won't collapse, but erode from where they are now.

A path to the decline could be decentralization of services combined with crypto currency. Money and infrastructure seems to be mostly what tech companies provide. Regulatory moats or other barriers to entry around payments logistics is a way they can still grip onto their positions.

Decentralized shopping, logistics (think decentralized Uber for package deliveries), and payments through crypto (BTC, stable coins, whatever), could be a path forward to break part of Amazon.

Web only services or middleman only services I think are a bit easier for them to sort of break out on their own, sort of like Lemmy and fediverse is. It'd just take longer for the quality of all of this to get better.

Hard to say, really. It would take a huge blunder from them to completely erase one of these companies from the map. Since they are so diversified in the services they provide, if one of their product dies they'll simply pursuit other business opportunities while relying on the other ones that are still doing great.

We can also go full pessimistic and think people will just stay chained to the websites and services of these companies. But if other great alternatives come up, people will jump to the next big thing.