You have taken the first step towards creating your own distro.
Seriously though, what you suggest is fairly common but really a matter of preference. The same answer applies to “is it just extra work”.
I tend not to customize heavily because it keeps “me” generic and I can sit down at anything and be equally effective. Others heavily customize their environments to keep themselves productive and happy on the machines they actually use.
One advantage of your approach is you can create a “standard” user space across multiple distos. You do not have to remember if this system or that is Debian or Arch if “rk update” works everywhere ( even if is doing something different under the hood. This could be useful if you run a bunch of VMs or containers.
Do you have a favourite text editor that you heavily customize or do you use whatever? Same question for your DE. It is all scratching the same itch.