The ground targets are not rendered when in cockpit view. They will only appear when you are so close that it’s already too late to use guns or rockets efficiently.
When switching to 3rd person view or ‘no cockpit’ view, same targets are rendered from way further away.
Easy test that shows the bug: In test flight, fly towards target and hit pause. Switch between the views.
3rd Person view:
Optics view (laser targeting in su-25):
Cockpit view. Target disappears:
No cockpit. Target reappears: