It does. However, the hotter the water becomes, the less effective the heatpump becomes. With anything beyond 60C becoming very inefficient.
With hot water tanks, they are unfortunately pretty badly insulated as well, with some of them loosing heat very quickly. Depending on how you plan on using that water, you also have to make sure the temperature never dips below ~60C to avoid legionella from spreading.
I actually think that heating your home slighly higher than you‘d usually do is the simplest and most effective approach, assuming it is properly insulated. Just rise the target temp for 1-2C when the energy is cheap and reset it once it isn‘t. Probably not as efficient, but extremely simple to implement.
The legionella thing is a little overblown fwiw. 50 degrees is perfectly adequate, and you can go lower with very little risk if you set it to briefly bump up to 60 every week or two. Even that is not hugely necessary in a domestic setting.
https://www.heatgeek.com/articles/legionella-and-water-tempe...
I think (hope) this niche will start to make a comeback as the underlying tech continues to get cheaper. You are starting to see glimmers of it in the low low end with some micromobility cars in Europe just providing phone holders instead of screens.