imo There is not a set age for when to supply tools for growth.
Simply because there are different reasons to invest in an education/training.
To start on the right track.
To stay ahead.
To not fall behind.
To get an edge.
To gain different knowledge to make educated decisions and find what works best.
Sometimes people start with entry level training and sometimes all the way up through technical high-level education/training. Or from basic equiptment ball bat glove to technical tools video analysis.
For softball different stages can be
Start with learning how to throw.
To then, developing a technical position like catching.
To then, how to have a faster pop time.
Learning how to hit the ball.
Or helping to create more power.
The education/training process starts when we're born.
Then gets defined by how detailed we'd like to be or need to be to reach our short and long term goals.