i really like the idea of wordpress as a headless CMS. Fact is whatever content platform we are building, while we add functionalities and features we are very quickly reaching the domain of content management systems (CMS), say a user system, a backend ui, ability to stage and review content of other contributors.
there are good solutions for all of those out there but all of them have to be built and made work with each other. A CMS is a big piece of work and i dont want to reinvent the wheel everytime i start a new project. There are also other CMS systems out there but lets face it, WordPress is by far the biggest one and it will be around for quite a while.
WordPress gets a lot of crap for a couple of reasons but mostly because its old. But its reasonably fast, reasonably secure, easy to set up and maintain and has a whole universe of plugins to extend it in every possible direction. Its a decent system and a "good enough" choice for a lot of scenarios.
Its the 1999 Corolla of the WebDev world.
Using WordPress as a headless CMS and combining it with a bleeding-edge react/svelte/vue frontend combines the best of both worlds. Use all the backend and CMS functionality from wordpress and focus your time and energy on creating a beautiful and engaging ui. Connect both simple simple-as-bread JSON api's or get fancy with GraphQL. Minimise your time-to-production and maximise your dev experience (if you like frontend stuff that is).