There are many frameworks for PHP. As a quite established language, some of them are a bit old as well. Symfony, Laravel, Yii, Codeigniter, CakePHP are some of the top frameworks. However, if you are planning to hire PHP developers with knowledge of the best framework then Laravel is the one.
Yes, PHP is a language that's in use for quite sometime. However, that does not mean that it is not going to be relevant in future. Looking at the popularity and community it safe to say it has a bright future as a backend language.
If you are planning to hire PHP developers and have a budget constain, then it is better to go for a mid scale Indian PHP development company. We are an Indian PHP web development company with more than a decade experience delivering excellence to Global clients.
As PHP is a backend programming language for web development, you can build web apps, web portals, websites, CRMs, CMS and many more.
PHP offers a strong authentication system as a backend language. Maybe PHP is not the most secure programming language but it offers ample number of features to make an application secure.