How to filter out bundles

Looking for whitelists?

theres SG-Tags but that doesn´t filter them out I think just shows you what was bundled next to the GAs

I have no idea if there is some sort of add-on that can do it automatically, but you can filter out whatever games you choose by clicking on the 'eye' next to the title of the game on certain pages that list giveaways. Of course this means having to manually add the games and keep up with anything that gets bundled. Not sure how many giveaways would be left if you were to do this though.

I generally want to feel that the devs are getting their full amount of money, so I dont get bundles

you aren't buying anything here, just getting free games from people.
with the same mindset you should be careful what giveaways you enter for unbundled games, since they can come from keys bought from g2a/kinguin and other resellers.

anyway, you could just hide them one by one in the main page, or use your steam wishlist and only view wishlist giveaways.