Google Cloud becomes a VC driven organization that slowly eats margin dirt against it's competitors until insolvency. There was no way for it to recover enough resources from the mothership before being split out.
Search trundles along ok, assuming it took search ads and a ton of core infra with it, but it never makes enough money to ship a decent product extension. It hopefully removes some products it can no longer afford margin on, which have long produced distorted results (albeit with good intention). It suffers slow brain drain, and users end up using multiple search engines for every search again because no one has good search quality. The monopoly breaks, but so does this part of the internet, bolstering apps and information sites ecosystems positions. Wikipedia is the only real winner we want in this space.
Display Ads goes like it just discovered faster than light travel, no longer held down by the ol ball and chain that is the entire rest of the company. They go much darker as they no longer have tons of goodwill organizing from the rest of the company, and increasingly join the bad actors. In 20 years they eventually join lexis level evil in terms of multi-directional user sharing.
YouTube heads off into the stratosphere along with Display Ads. They try to maintain a better public face, but having to spin up their own ad market solutions drops ad quality even further, margins suffer, but their position remains ossified and they slowly recover. They start to get a bit more agile, no longer disrupted every other year by some mandate from the mothership, they're better able to keep up with new markets and more rapidly crush new competition.
Workspace decays very slowly. All the AI stuff halts and gets ripped out as there's no one there to work on it. The drive product has to scramble to figure out how to rebuild without all the internal commodity infrastructure support. GMail gets unstable for a while due to the weight of the infrastructures sitting on many fewer shoulders. Global instability results of the rapid de-distribution of the system as the production infrastructure was sliced apart in a rush to meet forced division. The economy takes a big dive as a result, as half the world loses email access regularly, bills don't get paid, etc.
Photos spins out into its own thing, and dies rapidly, as selling the odd photo frame here and there just can't meet margin.
Chrome tries to get funding from Microsoft, eventually it gets purchased wholesale, but the core team gets ripped up and largely discarded. Who knows how the OSS products fare, it depends on the executives in Microsoft who win this purchase. Eventually the main product gets shuttered, with Edge being the only replacement.
The telco products all shutter immediately, with no recourse. Same with R&D.
AI tries to split out into it's own thing, but fails to find a business and suffers constant reputation problems. After 10y of trying it eventually shuts, the acquiring company however immediately spins up multiple successful products and makes a big dent in the now well established market.
Android spins out into its own organization. The first decade the heat of internal politics in new found vacuums crushes them, eventually they find footing and head back to their open core roots, get scrappy and do some new things. Along the way their size fluctuates as the market forks and fractures as it does, but Android manages to hold its position as the western center of its universe.
Chromecast, ChromeOS, Nest all suffer badly having no core ecosystem to ship anymore. They attempt to buddy up with Android which pushes them around trying to androidify everything, but resulting in poor UX and/or poor margins across the board. Eventually the all but ChromeOS shutter, and ChromeOS business also closes, but leaves behind an OSS gift that a core group of passionate individuals try to limp forward as best they can with the new Microsoft Edge overlords.
Users find their data fractures across a dozen companies, with poor SSO integrations. Security mistakes abound, lots of people are affected. Online crime goes through the roof, it feels like the 90s again, but on a much much larger scale. Lots of people lose their accounts, and are affected by service outages and the ongoing economic effects from those. ISPs jump at the chance to step in, and lots of users start trying to use alternative email services again. They experience poor discoverability, lots more security problems, and constant space pressure. Vultures make off like bandits, and amazon, apple, microsoft, and cloudflare are the biggest winners in the fallout.
In this world, Amazon et al get the same treatment. As for "vultures make off like bandits", welcome to market-based economics, these companies can compete if they don't want to die, and if they can't compete, then let them die.