You are correct that the RTSP firmware will not be continuously developed with new features, etc. The reason the RTSP firmware was not incorporated into the production firmware wasn’t because Wyze didn’t want to. It is instead because hardware limitations meant that is just wouldn’t fit alongside the regular firmware.
As for simply accessing the camera over the local network without internet access (no RTSP), you may want to hop over and vote for and or comment on the following Wishlist topic:
You can search the Wishlist and Roadmap using these links:
Search Wishlist (enter your search word/s after Wishlist in the search box)
Search Roadmap (enter your search word/s after Roadmap in the search box)
Please read through How to Use the Wishlist and How to Read the Roadmap.