Is it me or is this feature really missing? If it is, I feel GoG is wasting quite some potential here to activate/involve the gaming community. To clarify: What I'm looking for is an option to jump from a game page to the relating community forum, kinda similar to Steam. Being forced to navigate via community, searching for the matching forum and clicking it feels unneccessary tedious.

It is an oddly absent feature. Here's a wishlist for it:

https://www.gog.com/wishlist/site/link_to_relative_game_subforum_in_the_store_gamecard_page

and for Galaxy users:

https://www.gog.com/wishlist/galaxy/game_specific_forums

I see. Thanks for the links!

Also, Galaxy does have a link to the subforum for each game, but you have to select the game first. The link is in the "More" drop down menu. Having the link in the library drop down menu would just save a couple clicks.

No just Galaxy. If the game is in your library you can select "Forum" under "More".

Hopefully after the profiles they will focus to polish the gamecard page.