It depends on what you want.
I was working a lot with bootstrap a few years back. However ended up, throwing everything out, except the grid system. Because it was too much work to customize it the way I wanted or needed it to look like.
I would say if you're building a website you don't really need bootstrap. You could go with something other like tailwind / tachyons or just a grid system.
IMO where boostrap really shines is rapid UI develoment. If you are building a backend for something and need a lot of various UI elements, it is really nice. You can build a complete functional and okay looking backend in a few hours.
However even there... there are better alternatives, which look more modern, like semantic ui, bulma and others.
It depends on what you want.
I was working a lot with bootstrap a few years back. However ended up, throwing everything out, except the grid system. Because it was too much work to customize it the way I wanted or needed it to look like.
I would say if you're building a website you don't really need bootstrap. You could go with something other like tailwind / tachyons or just a grid system.
IMO where boostrap really shines is rapid UI develoment. If you are building a backend for something and need a lot of various UI elements, it is really nice. You can build a complete functional and okay looking backend in a few hours.
However even there... there are better alternatives, which look more modern, like semantic ui, bulma and others.