One of the compelling things for me is the ecosystem of bootstrap-based "themes". As a developer with enough design sense to realize I can't do design, I love I can work with a simple markup format and more or less drop in a theme to get a decent look, without having to think a lot about design or have an actual designer. For the internal tooling I primarly work on, bootstrap has meant a vastly improved look and feel over what I would have done before.
From this perspective, Bootstrap is basically an API you can develop against.
For customer-facing products and websites (where you can have actual designers involved) it's maybe not as compelling, or even a negative ("oh look, a bootstrap site"), but it's fundamentally not a worse choice than any other framework or programming language.
would it be possible to use bootstrap-themed components with css grid? It appears you don't have to use bootstrap positioning to use bootstrap theming.
From this perspective, Bootstrap is basically an API you can develop against.
For customer-facing products and websites (where you can have actual designers involved) it's maybe not as compelling, or even a negative ("oh look, a bootstrap site"), but it's fundamentally not a worse choice than any other framework or programming language.