I've been bewildering about setting the niche of my blog. I wanted it to be a multitopic based blog including science posts, beauty hacks, it stuff etc all that maintained in different sections/menus. However, as per my recent learning from some well-experienced national and international bloggers, making one's website based on different niches isn't a good idea as far as seo is concerend. They say when the site is full of multi-field topics, search engines don't prioritize them and instead give preference to sites that are solely build on a particular topic/topics. Also, people unsub the blog if they had subscribed it for some other purpose and see some other stuff from that site later.
What do you have to say about it?
What if I produce content on multiple niches, each with an enough word count and well explained? And choose topics that fascinate the general public?
I am more interested to keep my blog an all rounder than to stick to some specific fields since I'll fall short of content if I do so. Also, as a beginner, I'll not be having enough traffic.
Kindly say your say on this matter. Also suggest that if my blog is based on multiple fields what precautions do I have to take to not negatively effect the seo rather to keep it positive?