There are pros and cons of Bootstrap just like there are with all tools. As an example, DataTables works out of the box with Bootstrap and Foundation, but not

There are pros and cons of Bootstrap just like there are with all tools. As an example, DataTables works out of the box with Bootstrap and Foundation, but not with SemanticUI. Same with Select2, Symfony, JetBrains IDEs. The more bespoke your application, the more Bootstrap will either be useless or counter-productive. But if you're building a standard UI, Bootstrap is great. It's easy to find junior devs who can use it, and there's good documentation and support.