Meta is planning to let people in the EU directly download apps through Facebook ads. They plan to take advantage of new regulation in the EU called the Digital Markets Act (DMA), which will force Apple and Google to open up their mobile platforms to alternative methods of downloading apps.
Android currently allows side loading, but it requires settings to be changed to enable and displays warnings.
As I understand it, the DMA not only requires platforms to be open to 3rd party software, but also restricts platforms from giving preferential treatment to their own services. So Google would potentially have to remove the settings changes and warnings to sideloading so that 3rd party software is as easy to install as Play Store apps.
Of course, we won’t know how this will really play out until 2024 when the act comes into force, and platforms respond to it. How closely they will follow the letter and spirit of the act remains to be seen.