As a photographer Instagram is pretty much over as a platform for me, there is very little content on there now I would call "photographic" other than a few accounts I follow, but those are shown out of order and with ads mixed in-between. The explore page has become a mass of memes, "viral" videos, half naked women, spam, reposts from reddit, reposts of other reposts, and so on. I can see the same content multiple times on the explore page, reposted over and over. I recently unfollowed most of the accounts to put an end to the "such and such liked this so we will show it to you" as well.
And of course, as per the article, you have a massive amount of accounts that are liking and following to try to get followers in return. Some of these are more obvious than others. If you use Tinder you'll have seen an increasing trend of matches wanting you to follow them on Instagram, because they want to up their follower count.
All that said, I'm guilty of this too. I have a personal Instagram account that I do very little with[1], but also an account for the gallery I volunteer at[2] to try to spread the word to people in the area - I have a script that will like + follow anyone that posts to Instagram with tags and/or a location in the village. This script has been running once a day for about 6 months, and I believe it has brought some people into the gallery.
I also run an events page on Instagram[3] with a script that will like + follow any content tagged with various programming related keywords. Looking at some of the accounts it's followed (or have followed us back) it's bizarre - you can see accounts in which the content is just someone posting images of their laptop once a day and they have follower counts in the tens of thousands.
Anyway, it feels as if Instagram is at a tipping point. It's no longer a platform for photography but now a platform for driving traffic to other businesses. I'd give it another year or two before it collapses in on itself or they do a root and branch purge of all the spam, which probably won't happen as long as it is driving revenue to Instagram/Facebook itself.
[1] https://www.instagram.com/leejebay/ [2] https://www.instagram.com/galeriealpine/ [3] https://www.instagram.com/perl_events/