One approach gives the right answer. The other approach is more computationally tractable. Computers are pretty powerful now, so we can afford the correct answer much more often than we used to.

As for what is more natural… I've seen a (frequentist) introduction to statistics, and it simply did not make sense. Nothing was justified, you just had to learn the stuff by rote and apply it in situations that look like they could use one tool or another.

Probability theory on the other hand is pretty obvious. The axioms required to derive it are ridiculously few and ridiculously intuitive. From there you get the sum and product rules, and all the rest. Always made perfect sense to me.