Jenkins uses a very old and patched version of Bootstrap's Grid v3.1.1 (release from 2014). This JS library is automatically included in all jelly views that use the layout tag. This has several disadvantages:

• The JS lib is 6 years old and outdated and is not compatible with other modern JS libraries (see layout hack in the bootstrap4 plugin to get BootStrap 4 working on plugins views like in the Warnings plugin).
• The JS lib has been patched and does not use the default 12-column layout. However, a 12-column layout is expected by a lot of different JS libraries with a dependency to bootstrap. E.g. the data-tables columns will use only half of the screen due to the 24 column hack.

It would make sense to replace this version with the corresponding new version of Bootstrap 4 (btw: Bootstrap 5 is on its way). Note that this may break the layout in some plugins that already use the 24 columns.