Ubuntu 24.04 LTS appeared in mid-April, widely welcomed by its countless fans. Very quickly, however, their enthusiasm was cooled once it became clear that, intentionally or not, the distribution came with a serious limitation.
Namely, DEB files cannot be installed through the App Center, the usual application used for this.
In other words, for distro users accustomed to ease of use, the familiar double-click behavior of a DEB file led to this.
Good news for those that use the App Center. I continue to use Synaptic or gdebi myself.