I'll just defer to Merriam-Webster[1]:

>the obvious or easy things that can be most readily done or dealt with in achieving success or making progress toward an objective

So not only can it be "obvious" rather than "easy", it is also in the context of "achieving success or making progress toward an objective". There is nothing in the definition that requires either this specific step or the overall goal to be easy.

[1] - https://www.merriam-webster.com/dictionary/low-hanging%20fru...