[2021] Paradox Launch without initiating via Steam

That is the error you get when you run Paradox Launcher.exe directly, yes. It is designed to only be run from Steam or our standalone Paradox client.

If you don't want to use Steam and don't use mods or MP, just run ck3.exe directly. If you do want to use mods or MP install our client, from

Play on Paradox technology | Paradox Interactive

Link your Steam and Paradox Accounts together and be one of the first to try out the latest Paradox technology. Join now and be part of the journey of building great services around our games. play.paradoxplaza.com  

That would be one for the launcher devs:

New launcher version: 2021.2

And now for some launcher updates. We're up to 2021.2 and it's mostly a fix version: Changes Upgrade to Electron 11.1.1 Fixes Attempt at fixing the sometimes occurring duplicate feed content Text overflow in the sidebar for longer messages... forum.paradoxplaza.com
All the best!