The problem isn't "RHEL ships ancient PHP for legacy apps".
The problem is "RHEL doesn't also ship newer PHP as an alternative and you need to instead rely on third-party repositories".
The problem is "RHEL doesn't also ship newer PHP as an alternative and you need to instead rely on third-party repositories".
For CentOS and friends there is https://www.softwarecollections.org/en/
https://access.redhat.com/products/Red_Hat_Enterprise_Linux/... are maintained by RedHat directly.