Talk about hyperboles. RHEL 8 is from 2018 and has had considerably more updates than Ubuntu 18.04. In fact some packages might even be newer than what is in 20.04.
Red Hat introduced modules with RHEL8, meaning they can easily make available more up-to-date versions of software if necessary. It's still not bleeding edge, but eg. PostgreSQL 13 was released on 2020-09-24 and that's available with support in RHEL 8 as a module. Similarly, you have eg. PHP 8, Ruby 3.0 and other software released after RHEL 8's initial release.
Modules are much nicer to use than the previous software collection system because they actually replace the "original" package, so it's just a straight version upgrade without having to worry about fixing configuration files etc. if it's compatible.
The trade off of modules, which it pays to be aware of, is that they have different support lifecycles to the distro they are in. They publish a list that is updates as new modules are released.[1] what this means in practice is that some appstream modules may only have a year or two of support, while other may have until distribution release EOL. For example, in RHEL 8 PHP 7.4 is supported until 2029, almost 9 years after released as a module, but earlier 7.x versions and 8.0 which are also modules have lifecycles that range from 18-24 months.
There's a lot of flexibility in this to support both those that need newer versions of things as well as older stable versions, just be aware and choose and plan accordingly.
Modules are much nicer to use than the previous software collection system because they actually replace the "original" package, so it's just a straight version upgrade without having to worry about fixing configuration files etc. if it's compatible.