like the sibling comment said, web apps are written in Symfony/Laravel, but the framework abstractions with web apps might not paint you a clear picture of how the core language has improved. it will give you a good idea what it's like to build applications.
my favorite part of modern PHP is how nice writing libraries is. so it might not be what you're looking for, but I remember being pretty impressed with the code quality of the Amp PHP library recently. the v3 branch is 8.x only and (I believe) is targeting the Fibers feature just introduced in 8.1
one of the best things to come with PHP are the community standardizations around things like interfaces for HTTP requests, logging, DI containers, and even code style standards. it makes for a very consistent experience when developing (at least when you're in the "new world"), since most newer libraries are all written in a similar style using common interfaces
my favorite part of modern PHP is how nice writing libraries is. so it might not be what you're looking for, but I remember being pretty impressed with the code quality of the Amp PHP library recently. the v3 branch is 8.x only and (I believe) is targeting the Fibers feature just introduced in 8.1
https://github.com/amphp/amp/tree/v3
one of the best things to come with PHP are the community standardizations around things like interfaces for HTTP requests, logging, DI containers, and even code style standards. it makes for a very consistent experience when developing (at least when you're in the "new world"), since most newer libraries are all written in a similar style using common interfaces