You are complaining about a "problem" that has been created by the different camera manufacturers, not Adobe. Camera makers insist on developing their own proprietary raw formats, refusing to conform to any standard. Consequently, Adobe has always from the very beginning had to provide support for raw formats on an individual camera basis. That means that every time Nikon or Canon or Panasonic or any other camera maker releases a new model Adobe has to create profiles for a new camera. Really! Don't blame Adobe for this mess. Adobe introduced the DNG format as a standard that all camera makers could adopt, making all this individual support totally unnecessary. There have only been one or two camera makers who have offered DNG as an alternative.
It's impractical, and I believe unreasonable, to expect Adobe to continue to support older versions of Lightroom by adding support for new cameras to them. It requires a complete rewrite and distribution of the program. And how far back can you expect them to go? There are still people using Lightroom 2. Do you really expect Adobe to provide support for them for a camera released in 2014 or 2015? The operating systems have changed, and so has software architecture. The most practical way for Adobe to provide new support is to offer software updates.
Adobe works hard to provide support as quickly as they can. And they provide the DNG converter free of charge. All this is an attempt to sort of standardized the raw format mess. But until the camera makers all decide to use a standardized format, Adobe and other software providers are forced to work the way they are working.