Samsung is still innovating. It's kinda like when the first Note series devices came out. First people made fun of it. Then when they saw how popular they were becoming, started to copy them. The innovation came when app developers started writing apps to take advantage of the larger screens and smart styli like the S pen.
Now that Samsung has shown that foldable devices are viable and practical, you will see more a maturing of the technology. Other OEMs are starting to copy...again. Like with large screen phones, it will be app developers to innovate by writing apps to take advantage of foldable display technology.
Your OnePlus example demonstrates that cycle perfectly. OnePlus didn't push the hardware technology forward that much. It is the software innovation that OnePlus implemented is what makes the OnePlus Open a very good device and noteworthy.
It's been the story of computers since the first digital computers were invented.