Ukies are finding it hard to crack the ring of mines the Russians have planted. This means an armored push is still far off. Maybe some mine-destroying tech is needed more right now.
Putin doesn't want to nuke himself, which is the most likely outcome of him trying to nuke anyone. Nukes are literally the most expensive weapons to build and maintain. Please look at the current maintenance standards of the Russian military, and tell me again how they have working nuclear weapons that they built decades ago, when nuclear weapons have an expiration date that is more like a year or two without maintenance.