Replacing founders with professional managers was the norm in SV until the mid 2000s and the Zuck era began. See for example Google with Schmidt.

The problem is about delegating effectively, especially in the case of delegating to executives. The issue is treating parts of the org as "black boxes" and optimising for the wrong thing as a founder. Some founders/CEOs delegate the things they don't want to do or aren't good at. Others want to reinvent the wheel in terms of what "managing" and "direct reports" means. Still others just want to set the vision and hire some "strategists" etc. (who's doing the work?)

Founder mode is basically optimising for the quality of the product down to the gritty details and keeping wannabe professional fakers that manage up on a short leash.