Why am I such a fanboy?
Because I can do ALL the stuff I want to do! I can build super robust, pretty emails (like this one, looks good eh?), and on the automation front, I can enable self-pacing, skipping weekends, and sending at my desired time — the trifecta. With Convertkit, you can set up self-pacing more easily, but you can't ALSO skip weekends or send at a specific time. It's kind of an "either, or" situation.
I've trialed SendinBlue, Active Campaign, MailChimp, Drip, Campaign Monitor, and Hubspot, and for EBCs, Mailerlite wins across price, functionality, and most important... service! Their service team is unbelievable. I'm not a Mailerlite shill, I'm just a happy customer (it's free for all of our desired functionality for the first 1000 subscribers, and then it's still super cheap thereafter).
So while there's no obligation to use MailerLite... it wouldn't hurt. I put a link to sign up at the bottom. And if you're wondering, "can I use Mailerlite for my EBC but keep my current ESP for other stuff?"... the answer is a resounding "yes".