Alphabet didn't break itself apart. It reorganized. There is a big difference. Standard Oil was broken apart into different companies.
Alphabet wasn't broken up. It is 1 company. There is a difference between reorganization within 1 company and breaking up a company into separate companies. Not sure how else I can explain it.
Standard Oil was broken up into separate companies - which eventually become exxon,amaco,mobile,chevron,etc. Alphabet just reorganized their corporate structure. Meaning after the reorganization, google, youtube, deepmind, etc remained part of alphabet. Exxon, Amaco, Mobile, chevron, etc were not part of standard oil after the break up.