Great question!
In my opinion, the answer is "yes!"

I haven't put any cash into Steemit, but I'm very well aware that a small investment of cash can give you enough SP to make a real difference.

In my early days, I had two strategies...
Writing good posts and trying to get people to see them by leaving meaningful comments on other posts - worked well enough, but not super fast.

Writing posts for various contests. That worked much better in those early days. Investing everything back into SP was vital too.

Now, I'm also on Discord groups which has given me a huge boost.

I'm also using a small number of paid upvoting services (manual curators for the most part) which also help to boost my posts as well as the SP coming in much faster. (The ones I currently recommend are: @zenbot - currently "resting", @treeplanter, @thundercurator and @minnowbooster for that instant upvote for getting your post going. I plan a future post on this topic.)

Everyone's strategies are different and by-and-large, there's no wrong way as long as you are producing good content free from problems of plagiarism, etc.

Thanks for the post.