Niche an absolute requirement?

Everybody on this forum told me: Find your very own niche and you'll be successful. My problem is:

I've found some potential niches but I'm not really interested in any of them. I don't want to blog or write about something I don't even care about. On the other hand the topics/keywords I would be interested in are already taken and/or overcrowded.

Any solutions to that? What did you do?

What I did in the VERY beginning was start an a low competition keyword.. Since it was the beginning of my SEO practices, all I wanted to do was see how fast I can rank high at a low keyword. Niche didn't even matter for me as long as I was able to see that I can get where I wanted to be.

Then I moved on to some moderate competition keywords and am going to soon move on to a niche that I prefer.

Basically all I'm saying is that niche didn't really matter to me in the beginning but it does now and you'll probably learn why it does once you really get into it haha.

Or you can try multiple things out and do some more research. Wish you the best of luck!