Most companies that I worked with use Slack, and most of them subscribe to a plan...
When I decided to consider getting a full-time job this year, I found myself dumbfounded knowing that the company that I'm currently in now doesn't have a paid subscription on Slack... I asked why; they simply told me, "Yes, there are advantages to having a paid subscription, but with the advantage of a free account, your message will not stay forever and will get removed from their system after three months, and this is very important to us because we have a lot of sensitive data..."
It makes sense...
Then I realized that there are a lot of upgrades in our life that don't sound to be an upgrade at all.
I'm guilty of those upgrades because I have a Canva Pro that I barely use.