The system is flawed.

My team counts new devs and juniors as 1/2 person from a point perspective when we are doing planning. Juniors usually get this sand bag until we start beating our sprint goals again.

Perpetually flawed. No matter how much resources you throw at fixing it.

There's a huge difference between "no system is perfect" and "the dominant process for development work in our industry completely ignores work that nurtures employees into being better employees."

The goal of agile, as implemented in most shops, is to get things done quickly and to establish a reporting cadence with management.

Nurturing employees, and indeed software quality, is the product of company and team culture.

The development process is concrete (and “SMART”), so that’s what many managers focus on. The cultural aspects are more nebulous, so they are ignored.

"...and a whole bunch of other important things."

Always.

The system sets the board rules. You play the game. No system will ever play for you.