Yes. Professional web developers do use bootstrap. They also use the tools and frameworks at their disposal that make the most sense for the project they are working on.
This isn’t to say that web developers read. front-end devs, necessarily think bootstrap is the best way to code a site. Bootstrap is typically just a means to an end once you take in all of the factors of the current project such as time, resources, skill levels of developers etc…
In my experience, web developers have typically preferred to keep their projects as minimalistic as possible by importing third-party code where they can. In some cases, this might just mean that they will use a smaller bundled CSS library like tailwind or blaze.
Web developers aren’t designers
It’s important to note the role that a web developer plays in the build of a system. In a smaller company, the web developer may also be the designer as well as the developer but in a larger organisation, the web developer will be taking specifications of what to build from the designers.
Is bootstrap bad?
In no way is bootstrap a bad thing. Considering the question asking whether or not web developers use bootstrap you should consider the source of the question. The question contains connotations that bootstrap is either beneath what a web developer should require to get the job done or that it is some kind of cookie-cutter approach to building a website.
Bootstrap can be used as a quick way to create a simple UI that will just work (but may look like a lot of other websites) if the developer sticks with the out-of-the-box defaults that are shipped with bootstrap.
Customising bootstrap
If you think of Bootstrap as a design system rather than a CSS library (especially considering the fact that bootstrap is both Javascript and CSS) then you can start thinking of customising it in the same way you would customise any other system, by configuration.
Bootstrap has a vast array of options available for the developer to set in order to bring the styling and behaviour closer to the goals of the developer.
Of course, you can just include your CSS last to override anything from bootstrap in the event you can’t find a preset option to tweak as you need.
Is bootstrap dying?
Bootstrap is not dying. Lots of sites still rely on Bootstrap. When Bootstrap was first released, the list of CSS libraries and frameworks for building sites was quite small. Nowadays we are blessed with choices, even within different tech stacks there are many choices. There is plenty of work for anyone who has worked with Bootstrap as knowing the nuances of the system is extremely useful to build high-quality web applications.
Bootstrap suffers from the problem that it is very easy to misuse the framework. For example, by setting class attributes to different elements you can build sites that are visually the same but differ quite significantly in how they operate. The canonical example for this is the use of the btn class. With this class, you can make a div, p, h1 etc… element look just like a button. The problem is that they are not buttons and therefore you will introduce accessibility issues into your application.
Is Bootstrap actively maintained?
There is a core team of active contributors to Bootstrap and the Bootstrap team actively encourages support from the community to help pay for part-time staff. Most recently Bootstrap had an Icon library update at the beginning of this year.