2d Depth of field

Why does the sprite not have near and far depth of field blur, only 3d objects have it. If the sprite is in front of the 3d object, adjust the 3d object and the sprite has depth of field, for example:

 

I use the URP renderer, not 2d. If you use the 2d renderer, the change in the depth of field distance of the 3d object will disappear.

 

Not experienced in this too, so just guess... I think, that DOF effect needs depth information. But sprite shaders do not write into depth buffer (it has "ZWrite Off" in shaders). So, effect is taking depth information below sprite.

 

Thank you for your answer!

 

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When would I add a similar sprite depth of field effect?