The RoR hype started to wane long before React. You're really missing a huge part of our industry:
- While most 2nd or 3rd tier tech companies don't need Google scale infrastructure, SOA in Java/C# and then Go is incredibly prevalent. Many teams never had a reason to even look at RoR and its considerably worse language and runtime.
- Good ideas from RoR were copied by pretty much every ecosystem; again, most people never wanted Ruby in the first place.
- While most 2nd or 3rd tier tech companies don't need Google scale infrastructure, SOA in Java/C# and then Go is incredibly prevalent. Many teams never had a reason to even look at RoR and its considerably worse language and runtime.
- Good ideas from RoR were copied by pretty much every ecosystem; again, most people never wanted Ruby in the first place.
- Plenty of small web shops simply stuck to PHP.