Microphone is most needed tools to make any kind of video from your smartphone or DSLR camera. You have a good video but if you have a poor voice record then your video quality is consider not good. Because of cheap and good smartphone camera is in every hand in this generation. So why not to film your hobby.
YouTube is so popular today to post videos. Everyday thousands of videos are uploaded to youtube. If you can create interesting videos on YouTube, then for sure you can monetize through Adsense and can generate some revenue. Today, many YouTuber make millions of dollar per month from YouTube.
So, If are interested to make videos definitely you want microphone. Great ways to go online and read reviews and select your product from online. I use BOYA BY M1 microphone and it supports smartphone and cameras. So, I highly recommend it to try. Here is a link you can buy: https://amzn.to/33s5Hw4