They're both backed by huge companies (ACE/Chubb...Lumico/Swiss RE).
The parent, no matter how sound, is not the one issuing the policy. When the sub-carrier retreats from the state, that block is closed. Those who cannot move are part of a block that is getting older and sicker. Eventually that block will go into a death spiral . . . typically 5 to 7 years after the block is closed.