In theory, yes, but in practice, especially in Google's case, that won't work. YouTube could probably survive on its own ( due to the astronomical costs associated we can't be sure unless Google share more numbers), but no other part of Google's consumer-oriented services, and even some of their business oriented ones ( G Suite/Workspace/whatever it's called this week) can't be profitable, ever, and are only subsidised by data at scale and ads.
How would you split Google into entities that won't go bankrupt within a year? ( And you wouldn't want that because it would piss off people and would help the cause of the anti-regulation and anti-government uneducated people). Maybe GCP, Android foundation, YouTube, rest of Google could work, but the "rest of Google" is still too big and too powerful.
Forcing them to open their data and platforms ( e.g. allowing other ad networks to access Google's tracking data and to serve ads via them) could diminish their monopoly, but it could also diminish their profits and force them to cut some less profitable parts of the company even more ( and that might be good).
Same thing with Facebook, just a bit easier - splitting off Instagram and Whatsapp will absolutely improve things, but the remainder is still to big and powerful. Twitter is even worse, you can't split anything.
Anti-monopoly laws and frameworks need to be updated for the modern world, because the logic that worked for physical assets, sales and infrastructure ( e.g. the US split oil companies and telcos along physical lines) no longer works for Internet companies.
You can use anti-monopoly laws to do other things besides just breaking up companies. You can force them to not use their other entities to advantage themselves over competitors (promoting google services over others in search results). You can force interoperability and prevent shutting out competitors. You can prevent buying up new companies that compete with a google product. You could enforce a minim standard for consumer protection and codify rights to access for customers.
Many power companies have government enforced monopolies across the US. They also are heavily regulated and limited in what they can do to prevent them using their monopoly to extort, abuse, or neglect consumers.
That doesn't actually matter. Its a 'poor Google' argument, not an argument against breaking up a monopoly. The new divisions would have to figure out how to survive, like anybody else in the market. Definitely 'not our problem'
Why break up totally different services in the name of monopoly-cracking? What's the monopoly on? In what sector would breaking it into different services decrease monopolies?
