AT&T still dominates telephone service. Most phone companies are renamed Baby Bells.

Facebook has the analytics information and wealth to buy any competitor.

IBM gave itself away to Microsoft when an exec handed Bill Gates a sweetheart deal for DOS.

Microsoft is still the dominant force in its original industry (desktop computing) which is still significant.

The Internet disrupted companies that weren't ready for it. Do you think something new is coming alomg to replace the Internet?

Even so, when one giant replaces another, so what? What problem does that solve? "When elephants fight, it is the grass that suffers."