With sketching, it's usually an accessible way to plan out your design, mainly because it can be done on paper without any of the delays and troubles when doing it online. Plus, it's flexible for anyone to switch from high and low production ideas on the same page, which allows the process to be more focused and structured properly. Plus, there are little to no distractions when you're working since there's not that much visual design here. However, going into this kind of workflow is done on a physical format; it's not easy to simply put in an application or export it as a PDF. Some will need to use a duplication product to actually do so. Not to mention, unless you're a really talented artist who can traditionally draw on paper, there's a chance you're sketched plan might not look so visually pleasing. Especially cause of software, most people who don't exactly have artistic vision can choose a template they can easily edit for their ideal style, along with putting plenty of media such as videos and photos into the plan. Plus, sketching will not kind of interactive elements into the work, no animations or any advanced techniques that software wire framing usually has. Plus, it's also impossible to make any timestamps on the plan or make any copies of it, ones that are at least editable. Plus, if you were hoping to work with other people in your project, there's a small chance you won't be able to collaborate with a lot of people, at least not from a far distance. Plus, there's also the off chance that some elements will become inconsistent if you're not careful with a pencil, not to mention there won't be any way to control z your mistakes, and a pencil doesn't always come off easily.
Going off of all these, I can safely say going digital will be the best place to plan out my project. I'm already more accustomed to doing most of my work online anyway, and the good majority of my work on projects for my YouTube channel is already online. I constantly need to contact my friend and cast online since many of us either travel often or live in far-off locations from one another. Therefore, it'll be easier to gain feedback on whatever we're working on (ie, videos, voice lines, animated segments). So ultimately, online is the way to go for my work.