There is no problem per se with 100% meetings, or even mental space 'starting out'
The issue is one of agency. Working for a place where you are not an independent agent, but where the corporate politics dictate what time you do what, when, who you can hire and fire, what your team versus another team does, who gets called when something breaks, and what priorities are what. 'Striking out on one's own' is an attempt to retrieve agency. Without agency you're working for a biweekly paycheck and pats on the back, but you're disconnected from your labor.
What priorities are what. If you disagree as a senior leader what priorities are set by management, and the fallout falls on your staff, it can be demotivating. Want an example? New tech management comes along, and now there are two giant platforms, each with their own tech debt and CI/CD automations. Management decides that rather than address frailties that cause outages in production (poorly architected Kubernetes setup, lack of monitoring, etc), that the priority is to take 30% of the DevOps staff and dedicate them for 6 months to converge on one CI/CD system. By the end of the 6 months, the number of outages has drastically increased, and the convergence has not been complete (still two separate CI/CD systems). Upper management cracks down harder on everyone. Another example. Tech management changes priorities every few weeks for everyone in DevOps, meaning projects remain half-done, people get context-switches from one tactical thing to the other, and people outside of the team complain that the DevOps team never delivers anything.
These are the types of 'if I were in charge' type of events that would not occur, as they were entirely predicted but overruled.
At some point, you become too old to put up with this anymore. And the mental space of the above frustrations is already 24/7/365.
The difference is that someone else gets to charge the clients.