Why do others say don't join all groups together ?

Several (new) users that request to join many group at once, do not read the rules & requirements of the groups properly and thus request in groups they do not qualify for. That can leave a lasting impression on group admins.

If you join giveaway groups with some kind of ratio system, you quickly get overwhelmed by the number of giveaways (of a certain quality) that you have to create. It is easy to lose track of your group obligations.

Edit: In your case, for some groups, the question will be, if you are able to provide giveaways that are not region restricted.

most people join groups only for giveaways and not for what the group offers or is about

I believe it has to do with the ratio for the most part. Great groups that you have a good chance of winning really messes up your ratio, making it more difficult to join others.

Take your time joining groups. Not all are gonna offer you entry, especially if you're new and haven't built a slightly good public reputation.

I'm surprised your friends from the full CV abuser RR Turkey bubble weren't able to answer you that question

Edit, as you closed the topic:

1.Neither me nor my friends are not CV abusers. I giveaway some of my favorite puzzle games here that wanted others to play it

double negation says everything

2.Region restricted giveaways are because I can't send gifts to other regions due to Steam rules

of course, Steam gifting is the exception here and suddenly you and all your friends use it, besides speedrunning to lvl 5

3.My region is Turkey because I'm both originally from Türkiye and travel to there a lot as most of my family members live there.

I never doubted your heritage

5.My friends either don't giveaway or rarely giveaway games here lmao

sure and suddenly you use the same schemes as the aforementioned bubble

last one: don't know what this "bubble" or "schemes" means and again read 5

right, all your knowledge about setting up region restricted giveaways, full CV abuse and speedrunning to lvl 5 is pure coincidence and the usual behaviour of new accounts lol