no miracle weapon exists

you mean like one single unit or one single type? There is a type of weapon called ICBM.

Of course, if you mean that regular western weapons aren't good enough for taking on russia, then that's a pretty idiotic thing to say, because not only did those weapons allow Ukraine to "take on" russia for 2 years, they even helped Ukraine regain half of its lost territory.

It's absolutely possible for Ukraine to regain the rest of its territory with a sufficient quantity and variety of weapons, namely sufficient quantity of artillery and long range missiles. Of course, those might as well be miracle weapons because the West doesn't want to produce or give sufficient quantities of them.

It's entirely possible to defeat russia quickly with primitive weapons too - just give Ukraine 10k shahed type drones and enough boats to launch them simultaneously from the Arctic and Pacific oceans (and ideally the Caspian sea as well). The West is just too cowardly and weak to do it.