Imagine chopping Search and Ads out to be their own things.
GoogAds turns into just another advertising company. Perhaps viable but uninteresting. GoogSearch, well, almost nobody wants to pay for search, so they seek some kind of way to get money, and the start up with the integrated ads, soon to result in what we have now. I used to run various Google Search Appliances, but they bailed out of that market.
Peel off GMail? More than zero people want to pay for email, so you might see something like a clunky Fastmail with a free tier and a pay tier. The free tier means ads again and you're evolving to a Yahoo model. Ummm, nobody really wanted that.
How about hardware? I dunno, are Pixels a loss leader for Google? I'll bow to someone else's insight on this, and I'm not really hip to the phone scene: are there a lot of "smartphones, we only make smartphones" companies?
Google Docs and various officeware might stand on its own as a distant second to Microsoft. I know some people pay for that.
Google Books, maaaaaaaaaaybe. It might stand on its own but here we just see people having to pay for what was once free.
I just don't see anything interesting or stimulating coming out of carving up Google. Almost everything they did (it has been a while since I was "into" them) seemed focused on making things that were almost byproducts, wherein their real utility was feeding the search <-> advertising cycle.