I think Phoenix is overhyped a lot. The barrier to entry is gigantic. The lack of up-to-date resources doesn't help. It's definitely not as polished as Laravel for example.
And while there is Pragmatic Studio with their wonderful introduction video, there is nothing like Laracasts where there are new tutorials added all the time. Frankly, it's on another level.
Deploying Phoenix is a nightmare when compared to Laravel.
In Phx you have to reinvent a lot of things and often, of course, choosing the wrong path.
Sure try the chat demo apps Phx is famous for but beyond that it's a pain in the ass unless you are very good Elixir programmer and can bug fix and reinvent-the-wheel things out.
Also, Phoenix is bad in environments with bad wi-fi. Think halls, kitchens, factories. So, I wouldn't do a Phx app for some warehouse2customers type of operation a because there are some very interesting out of connection problems, the necessity to constantly ping/"hearbeat" home to the server.
For me it is a pass. The experience with 1.6 and 1.7 rc was bad.
P.S. One extremely important thing, PHP is made for sloppy web programmers (like me). It will forgive and brute-force-work like hell when needed. Elixir is less forgiving and you can shoot yourself in the foot much easier. That's why I prefer PHP - it's much easier to put up some website that works well even on a cheap hardware and then you can PHP-optimize and tinker if you want.
P.S.S. The speed thing is overhyped as well. PHP vs Elixir for web stuff is not as big difference. In Laravel - if you use PHP 8.2 and cache your views, routes, etc. the DB stuff is still the 80% of all of your problems, not the PHP or Laravel.