@AmitVishwakarma Amazing question, over the years I have seen AEM swing from the strong single place that holds every piece - Headful content (assets + authored pages) + code (components, services) to somewhat a Hybrid/Headless container for which gives everyone flexibility on how to consume (you decide - framework & mobile/web/kiosk, delivery rules).
Good : Decoupling AEM authoring to just switch it to a content provider (Sling API, GraphQL and other tools) which makes performance improve, drastically, allowing levearing mordern frameworks, and ofcourse multi-platform.
Bad : In retail business, the authors love to deliver the content in WYSIWYG form, being able to drag and drop and simply publish, allows business to have somewhat 'control' over content which is lost in as we move towards Headless. So, it depends what is priority, data is easily consumed through say GraphQL and delivered entirely via Dev team, using complex architecture delivering to mobile apps
But again going past jargons and diplomatic answers, I will personally say, unless AEM is used in Hybrid model where we somewhat use its power as a CMS, moving towards Headless despite being great is still something I will not prefer, because than, there are other ways to store and retrieve content, a powerful (and expensive) enterprise product should be used only if we use it to maximum extent, if we are partially or fully using it as somewhat 'datasource', then it doesn't justify the cost. Well, that's what I feel.
Verdict - Short answer 'It depends on architecture, who is consumer, you prefer dev controlled app or better performance, is it SPA or mobile app.
Longer answer -
Type Best For When to Avoid
Headful | Corporate sites, landing pages, intranets, sites where authors drive UX | Multi-channel, modern SPAs, mobile apps |
Headless | Omnichannel delivery (apps, kiosks, smart devices), developer-driven UX | Pure marketing/author-driven sites |
Hybrid | Enterprises needing web + app + IoT support, while preserving authoring | Very small/simple sites (adds complexity) |