It's a mixture of multiple things including all that was already said.
Remember, when this forum was first started the main topic and android device for Verizon was the Droid. Between the activities surrounding the development of android happening at the ground level with ROMs, people looking to add or make do with features missing that was on the competing iPhone, and the Droid being the direct competition to the iPhone (and at the time the closest thing we could get to an iPhone on Verizon for those wanting an iPhone), and this all help make this place the place to be.
Over the years we started to see the activity level decline as we saw more devices which stretched members to specific device related forums.
The same can be said with ROMs. As phones started to improve and incorporate features from Roms as standard, the excitement for the developer community dwindled.
With the main talk being about new phones and android builds, we are seeing more focus going toward social media, news sites, and YT videos. Forums are mainly a source for information (ie think tech library) now.
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