As a freelance writer and blogger, I have been in your shoes.
To make more money as a freelance writer, you need to establish yourself as an expert to ditch the abysmal rates you must charge to find clients on platforms like Upwork and Fiverr.
To find clients to pay you what you are worth, you need to niche down and become an expert in one primary topic or industry.
As a blogger, you need to niche down for similar reasons - so you can showcase yourself as an expert to help Google understand what your blog is about.
And this will help you find your true audience and tailor your messaging to them so you can sell more affiliate products and make money with your own products and services.
It took me a year to choose my niche for my blog and my writing businesses! I tried emailing the bloggers whose list I was on, asking in Facebook groups, and doing anything else I could to narrow my topics down.
I'm still waiting to get responses back because, unfortunately, only you can choose your niche. Eventually, I had to create separate websites from my blog and writing business because they were just too different.