What determines the path in radioactive decay series? How an element decays can be plotted in a diagram like this:

source: https://chem.libretexts.org/Courses/City_College_of_San_Francisco/Chemistry_101B/10%3A_Nuclear_Chemistry/10.3%3A_Radioactive_Decay
What determines the path taken of uranium? Since in quantum mechanics the resultant path can be seen as a 'superposition' of paths, is this also de case for radioactive decay?
EDIT: why is this path not possible?

 A: Some isotopes have only one possible decay mode; some have several. The first few steps in this $^{238}\text U$ decay path are fixed, up to $^{226}\text{Ra}$. But as well as decaying to $^{222}\text{Rn}$ by emitting an alpha particle, $^{226}\text{Ra}$ has two alternative decay modes - it can decay to $^{226}\text{Th}$ by emitting two beta particles, or it can split into $^{212}\text{Pb}$ and $^{14}\text C$. These alternative decay modes are much rarer than the alpha decay mode, but which one happens for a particular nucleus is a matter of chance. By collecting enough data we can empirically measure the relative probabilities of different decay modes, but we can't predict which one will occur for a particular nucleus.
The other variable, of course, is the time taken for each decay to happen. There is a $50 \%$ probability that each decay will happen within a given period, called its half-life, but the exact timing of the decay for a particular nucleus is again a matter of chance.
A: I will try to answer one of your questions in a general sort of way here.
For any element heavier than ~iron, the amount of energy released in decay exceeds the binding energy holding the nucleus together and so there will be a tendency for spontaneous decay to occur as the atom strives for an energy minimum. This means uranium "wants" to travel generally down and left on that chart towards the most comfortable spot at iron 56.
For each different isotope/nucleus in this chart, there will be a specific binding energy (trying to hold the whole shebang together), a specific activation energy (required to kick the nucleus over the hump and thence into action), and a net energy difference between it and its nearest neighbors "down" on the chart. The interplay between these factors will determine how likely a certain decay path will be, what the associated half-life will be, and whether the decay particle will be an alpha or a beta and how big a gamma release might be.
This is a complicated business which will involve other stuff I have not mentioned here- like, for example, the fact that on this chart there are several "magic spots" where the particular occupant of that spot is particularly happy (i.e., stable) and other decay paths that are "locked out" and unavailable to the unstable nucleus.
The sum of all these considerations at every possible step in the decay chain is what causes all those zigs and zags in the overall chain.
