Is our pussy willow dying?

We had this willow pollarded in Dec 2023/Jan 2024, which took two thirds off its height. During 2024 there was vigorous new growth as expected. However, in late August or early September, all the leaves darkened and fell within a matter of days. I posted on here at the time, and people thought it might have been drought, as the summer was dry. (We hadn't thought of giving water to such a mature tree.)

Over winter, we brought in a lot of topsoil/compost mix and lay it over the surrounding area, raising the soil level by 2 or 3 inches. This was in preparation to plant some shade and drought tolerant perennials under the shadow of the tree and fence.

However, the willow now looks almost dead. It didn't seem to produce any catkins this spring, and there only a very few tiny groups of leaves forming on last year's growth and side shoots.

We were looking forward to planting the area a little more (with our eyes open to failure if the willow sucked up all available water), but now I'm half wondering if there's no point and we need to remove the willow altogether?