I am never satisfied with the grass/mulch edge; mulch looks great when

periodically rake or hoe the mulch to keep it looking fresh.

When you mow, make sure to mow so that the grass doesn't blow into the mulch area. Most of the time the lawn companies just blow the grass out, they probably just angle the blower so that it doesn't blow the mulch away. I doubt the mulch deteriorates that fast, maybe it is the grass left on it. Perhaps if you spray it with water to rinse down the grass, etc. that gets on it. It could perhaps be getting dust and dirt on it due to yard maintenance.

When mowing/edging, make certain you direct the cuttings away from the mulched area, then sweep/vacuum them up for your compost bin

There is edging you can buy that you hammer in almost to the surface of the lawn. This keeps the mower from messing up the mulch and the mulch will stay where it belongs. It is easy to install.

Have you tried an edging? My mow and blow guy is good and not expensive. I used to do my own but after multiple back surgeries and a few other things, I had to cave in and get help. My place looks pristine when they leave.

One of our client residing at Redmond faced the same problem. So I would suggest you to first know the benefits of mulching and it's impact. You can get help from here: Top 7 Benefits of Mulching Your Garden

Now let's get to your problem., you can easily get any professional to do your work and that too properly.

You can consider Premier Concepts expert service for your property.