The strength falloff of the brush can also be created on “Brushes Panel > Create a new brush using curves”.
This option is open pressing over the “+” icon to create a new brush type

a popup open showing the option to Create brushes based on Curves:

Selecting this option you can create your own library of shapes based on curves Fall Off.
The “Edit Brush Shape panel” show options to edit forward, left/right and radial falloff, as well as the option to select any texture as depth alpha on “Depth texture path”.

Click on curve to insert point. Click RMB to change point type (precise, smooth, sharp). Press SHIFT and drag point to snap. Doubleclick to remove point.
Texture bias: The additional displacement of the texture.
Auto bias: calculate the displacement depth based on current texture grey values.
Texture scale: Additional texture scale.
Rotation: Rotate in screen space.
U/V offset: move the texture on U/V space horizontally or vertically.
Flip U/V: Flip selected faces horizontally or vertically.
The brushes based on Curves can be used for any sculpt tool too.

The “Tool options > Modifiers” have the option to use the current alpha selected on Brush Panel or Edit the bush shape using curves as was show before.

You can also control the strength falloff of the brush by adjusting the “Falloff” settings in the Brush top bar controls.
This allows you to modify how the strength of the brush decreases from the center to the edges, giving you more control over the brush’s effect on your model.