I have seen people doing this, and while it certainly increases your number of followers into the thousands, it is very clear that it is doing very little to increase their earnings or success in the platform.

Most users who use this strategy make less than a dollar per post even though they have literally thousands of followers. This is mostly due to two things:

1. People who do this are usually producing low quality or copy-pasted content.
2. Most of these followers they added at random don't read or care about the stuff they produce.

So why even bother? Just follow whoever you want ;-)