Ivy overtaking trees capacity to photosynthesize

There's mature and more juvenile trees here. There's ivy too and whilst I appreciate the value of the ivy to provide food for insects, homes for creatures and to absorb pollution from a busy traffic way, the ivy is now so huge and mature that a lot of the trees are struggling to phootosynthesize. The ivy was managed in the past but I think someone knowledgeable should have a look before the trees are weakened enough to become diseased or vulnerable to pests which will mean that they could die or need felled