[CentOS] where are all the Redhat 8 -devel packages?

I'm probably missing something really simple.

I've installed an RH8 IAM in AWS and I'm trying to build packages on it. 
I've noticed there are many *-devel packages that I cannot install:

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[ec2-user at site1-vpn ~]$ sudo yum install trousers-devel
Last metadata expiration check: 1:10:41 ago on Thu 04 Jul 2019 01:01:14 
AM UTC.
No match for argument: trousers-devel
Error: Unable to find a match
########################################

However, if I download trousers-0.3.14-2.el8.src.rpm from Redhat and I 
build it on my RH8 instance, it builds the -devel package:

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Wrote: 
/home/ec2-user/rpmbuild/RPMS/x86_64/trousers-0.3.14-2.el8.x86_64.rpm
Wrote: 
/home/ec2-user/rpmbuild/RPMS/x86_64/trousers-lib-0.3.14-2.el8.x86_64.rpm
Wrote: 
/home/ec2-user/rpmbuild/RPMS/x86_64/trousers-static-0.3.14-2.el8.x86_64.rpm
Wrote: 
/home/ec2-user/rpmbuild/RPMS/x86_64/trousers-devel-0.3.14-2.el8.x86_64.rpm
Wrote: 
/home/ec2-user/rpmbuild/RPMS/x86_64/trousers-debugsource-0.3.14-2.el8.x86_64.rpm
Wrote: 
/home/ec2-user/rpmbuild/RPMS/x86_64/trousers-debuginfo-0.3.14-2.el8.x86_64.rpm
Wrote: 
/home/ec2-user/rpmbuild/RPMS/x86_64/trousers-lib-debuginfo-0.3.14-2.el8.x86_64.rpm
########################################

Same issue for json-c and json-c-devel and other packages.

What's going on, what is the little detail I'm totally missing?

I've checked the repositories in yum, I think everything important is 
enabled.

-- 
Florin Andrei
http://florin.myip.org/