There are lots of companies that entertain this solution. There are just very few examples of it working for the simple reason that this advice generally doesn't work. We look at the one company that succeeds and "say why didn't we just do that?" without remembering that there were 10 other startups that failed. The more reliable solution is to use the same wisdom of hindsight to pick winners and just buy out the one that succeeds. Facebook bought instagram, but none of their internal efforts have produced anything so useful.

Hmm, could you give a few famous examples that “failed”?

Cisco tried a fairly extreme version of this, but a new CEO put an end to it due in part to morale damage in the bulk of the company not working on those projects: https://www.ft.com/content/a81c934c-cb31-11e9-af46-b09e8bfe6...