We get this question aaaalot! 😅
In short, software like Mailchimp/ConvertKit/Outfunnel (and so many others) are sales/marketing software that you would use to send bulk emails to multiple contacts (e.g. newsletters, cold outreach, etc).
When sending cold sales/marketing emails, contacts can identify that the email is automated/bulk as these emails must legally have an unsubscribe button. They know they are a part of an automated campaign.
Efficient Email Automation, on the other hand, allows you to send what is called transactional emails. These are emails that you would normally send manually person-to-person (onboarding emails, status updates, follow-ups etc). These emails are sent straight from you, as if you opened up your Gmail account and sent them from there.
There is no unsubscribe button, and emails are also more likely to appear in the important section of the inbox as that's where 1-to-1 emails go.
So in summary, Communicate (Email Automation) is great if you have a process where you would constantly send the same personalized email over and over at different stages in your process to touch base with your prospects, clients, or team (internal). Marketing software is normally a must-have these days for generic outreach.
We find both necessary and therefore we use both.