Both of you need Original Content
Both go on the strength of the content. People will come to your blog to read your articles, and to watch your videos on your YouTube channel. People will like to visit such blogs which will have many useful articles and such YouTube channel which will have lots of great videos.
Both require some small investments
However, both are free to start. You can create a free blog on Blogger and can also upload videos for free by recording video from screen recording or mobile etc. on YouTube. But if you want professionalism, then you need a self-hosted WordPress blog and invest in YouTube channel for great content, great camera, mic etc.
Both give results in the long term
Remember one thing, both things will take time, before you get any result, or else you can start earning money from them. None of these is overnight money making technique. It can take from 6 months to 1 year for Blogs and YouTube channels to give you good results.
Both are great ways to earn money and to reach people.
If you run a blog with hard work or a YouTube channel with proper techniques, then you will benefit, even in terms of money and according to popularity.
Would it be great to do both Blogging and YouTube together?
You can also do both things together. But again, two things matter, time and efforts. If you have so much time that you can do both things together and you can put all your hard work for it, then you definitely do.
Most people do not even have enough time to be able to do either blogging or YouTube in favor of their business or job. Now it completely depends on you how much you can devote yourself to this work.