Honeysuckle is killing forests and ivy is helping, especially in the northeast/midwest. Kill all that shit, help stop it from spreading. And try to volunteer for local groups that are clearing invasive species. It's pretty amazing seeing a forest before and after invasive species have been removed.
Yep, repeated treatments over the course of years ,whether manual or chemical, is the way to go. Great job, I’m sure you’re seeing some pollinators on your property now!