ChatGPT has a React fetish but not as bad as Claude's fetish for React. Tailwind support would be amazing as currently implementing it is a manual task. There are several requests to incorporate Tailwind but not sure any of them has gained enough traction as of yet...
There is nothing wrong with Bootstrap. Personally and within our organisation we develop primarily using Bootstrap for 90% of our applications (internally). That other 10% is a mix of Tailwind and custom styles and classes based on Client requests. As for which Framework is better that is a little like arguing over Football teams. The fallback is creating your own CSS to achieve exactly what you want. In that regard there are no set specifics and it is entirely up to you.
Its swings and roundabouts essentially! One thing that is not in doubt is the fact, like you mention above, is that any of the above is far superior to Wordpress if you want full control. Don't get me wrong Wordpress has its place and am not knocking it. But we are all here as we like to control our development process to a greater extent which is something Wappler allows us all to do. So why does Wappler use Bootstrap..? I can't answer for the Team as to why they made that choice but one reason is its shear popularity and ease of use. The support for Bootstrap is huge, it is well documented, tried and tested, and free. Probably all major factors. But things have moved on since the initial Wappler release several years ago hence the requests for other Frameworks to be implemented. Am sure in the future they will be provided for but for now you'll have to integrate those yourself.
Not sure if that aids you in any way with regards to your question though...?
We Developers are like Chefs. We'll essentially cook the same dish but use different ingredients to spice it up and add our own flavor to it. No set menu and all open to interpretation by the cook making the dish. Now and again we'll burn the food but most of the time the dish comes out fine and dandy. Wappler is the kitchen and we are the Chefs.