Here's the reality of what happens to a lot of "retained" trees in subdivisions.
The road was diverted around this old Jarrah (Eucalyptus marginata) but less than ten years later it's dead.
This Marri (Corymbia calophylla) was incorporated into the new park but it's not long for this world either.
By way of contrast, here's a tree just outside the subdivision that has been left relatively undisturbed. Nary a dead twig to be seen.
Developers get brownie points for "retaining existing trees" but no follow up surveys are done to see how many actually make it.
The answer of course is better design. Design that actually takes into account the needs of the trees.
It's not hard but it costs more.
Ah, now there's the rub. But what price do we put on these things?
What it boils down to is whether we truly want to save trees or just want to be able to say "we tried".