Depends on what you mean by "best". If you mean best as in quick to launch, performant, and easy to maintain, then I'd say PHP because it was built specifically for web development.
The problem with PHP is that it's too easy to use and apps built with it have low maintenance costs. Which means that your ownership over a code base can easily be transferred to someone else.
If you want the best tech stack that will prevent you from killing the job, then I'd say Typescript or Java based API and a front-end framework like React. The more complex the code, the harder it will be to replace you and your team.
The problem with PHP is that it's too easy to use and apps built with it have low maintenance costs. Which means that your ownership over a code base can easily be transferred to someone else.
If you want the best tech stack that will prevent you from killing the job, then I'd say Typescript or Java based API and a front-end framework like React. The more complex the code, the harder it will be to replace you and your team.