I remember I heard about Adobe moving into the CMS business in 1998 or 1999.
I'm glad they finally got around doing it . . . ;-)
[0] https://w3techs.com/technologies/details/cm-adobeexperiencem...
Wix, Squarespace, and Shopify are Tier 3 CMSs at best.
Drupal, (managed) WordPress, Joomla, Cake, Webflow etc. are Tier2.
AEM, Sitecore, BloomReach, Contentful, Contentstack, etc. are Tier 1
The CMS ecosystem is further segmented into products that are headless, decoupled, hybrid, and monolithic. To complicate things, there is a new type of product called DXP (Digital Experience Platform), which mixes in marketing systems into the stack.