Working online, and make money with it, was easier 10-15-20 years ago. Nowadays starting a blog is like to play at the lottery. You can win, but you are more likely to lose. There aren't profitable niches, because everything could be a niche, and could be profitable. There aren't profitable keywords, because they change every day, or a week, or month.
When we say "a blog wins", what are we referred to? Thousands of visitors? Or many customers that buy our products or our affiliate products? Or it ranked #1 on Google? Or it has many readers and followers?
What is the purpose of your blog? Make money or find people with the same passion, or share what you do simply. The purpose affects the strategy.
If you want to make money, you need to spend money on tools, ads, pro writers, etc. If you don't want to spend money, you have to spend time, a lot of time.
In conclusion, I think blog fails because you don't invest enough money or time to grow the blog. If you spend money your blog will grow fast, but time is limited. If you don't want to spend money, you need to spend a lot of time... this means that you cannot compare a blog born a month or a year ago with a blog that's been online for 5 or 10 years or more.
Passion, time, money, perseverance, and resilience... these are the ingredients for the winning recipe.