Q: What does Mailchimp do that Hubspot cannot?
Short A: You're comparing 'apples' to 'orange'. (literally)
Comparing Mailchimp to HubSpot is like comparing Batman to Superman -- both may be superheros, but only Superman has native abilities with or without his costume.
Mailchimp is a newsletter email service provider (ESP) turned ESP turned pseudo marketing platform turned pseudo ecommerce marketing platform with little CRM capability.
Like Batman, Mailchimp has a great 'costume' -- their excellent marketing as a do-it-yourself (DIY) email automation platform AND their newly updated drag-n-drop email designer. Also, like Batman, Mailchimp has cool tools -- audiences, groups, and (limited) segments.
However, HubSpot is some 'other world isht' -- a fully mature marketing automation platform with certified integrated ecommerce (e.g., Shopify, WooCommerce, Magento, BigCommerce, etc.) that also includes a native CRM and conversational marketing.
Like Superman, HubSpot has a great 'costume' -- their prolific inbound content marketing machine which freely allows reuse (with attribution). Also, like Superman, HubSpot has cooler tools -- native smart lists which are auto-updated based on criteria you set giving you 'x-ray vision' into your CRM, and workflows which allow you to basically 'program' the automation around nearly anything you can dream of (within reason) -- sorta like making the Earth spin faster to travel through time.
When stripped of their costumes, MailChimp (like Batman) is absolutely no match for HubSpot.
In fact, it's not even a fair comparison. We're talking humans compared to aliens who gain superhuman strength simply being in the presence of a yellow Sun -- aka: HubSpotters! haha
Make two lists ...
-- one for awesome email service providers trying to become marketing automation platforms with newCRM capability (circa 2019).
-- one for fully mature marketing automation platforms with native CRM capability and super human strength built-in.
Then decide which will best serve your needs because the costs of both purchasing and operating each are dramatically different.
Hope that helps. Good luck with your research.
[Reposted as a HubSpot Community solution 20180421] - What Does Mailchimp Do That HubSpot Cannot?