It only looks like failure of market regulation in retrospect for companies like Facebook and Google (Microsoft is a bit different) because these companies grew

It only looks like failure of market regulation in retrospect for companies like Facebook and Google (Microsoft is a bit different) because these companies grew businesses that simply hadn't existed before. How do you regulate Google buying something like youtube when youtube was a loss maker at the time, they grew it into a titan. Same with android, smartphones in the form of the iphone were brand new, who was to say at the time that Google would win with all the other companies building smartphones at that time.