I always hear the argument "you don't need a fancy website or UI, when I started my site/app looked like ___"
These people created MVPs in 2010. You're now competing with MVPs that can be built with way more features, the latest tech stacks, and more in the same period of time.
This can proably be attributed to the barrier for entry for competition being so much lower , so the definition of an MVP has changed. And equally, expectations from end users have risen. Recent anecdotal example of this is the frenetic pace of development in the ML/AI space with opensource tools like Stable Diffusion practically almost rendering moot the business model of OpenAI’s DALLE-2.
To win out MVPs have to either be a value proposition currently not available that people need, or to win a popularity contest based on UX, design and branding. That there are still project management tools being developed and succeeding in a saturated market tells me that the popularity contest never really stops.
What makes you want to use Elixir, Phoenix, and LiveView? I've never even heard of these before
Back when I dabbled in web dev in college, people only talked about the MERN stack lol