Blame the monkey for this one ...
Writing groups are odd beasts. I've been part of a few IRL ones (both for writing and poetry) and two online ones. I got spoiled by the first online one in the late 90s since it did focus on the writing, had a lot of submissions and we critiqued and cheered on each other's work. It died when the founder got too busy to keep it going, which happens, and I am also looking back through a fifteen-year lens at it.
Critiquing is hard, but boils down to a balance of criticism, being constructive and giving compliments. Not the 'awesome!' sense as much as 'this line rocked because...' or 'this scene was spot-on' and the like. Telling someone what they did right is as important as pointing out where a story goes wrong.
The group itself is the harder creature to get right. You have the people who want to write for a hobby, the ones serious about wanting to be published, ones who think they should already have been published because they are pure awesome and people for whom it was just a lark and they aren't serious about it at all. As long as everyone wants to improve, such groups can work though it does work best for the ones for whom writing is one of their major passions.
So there's that. But the issue of critique to submission is vital as well. People write at different paces. Some like to share unfinished work, others should never do so. (See: me. My first drafts are terrible.) And everyone has slumps when they have no creative energy at all and aren't sure where a story is going. It happens. But a writing group can make one feel compelled to produce, or not wanting to remain if one doesn't have submissions even if their critiques are valid.
I suspect that a solid (and large) online group is better suited to navigating these issues. The danger is that all such groups move away from writing at times. You can't have a group just focused on one subject forever, and I find online ones tend to devolve into the general chat areas while the writing stuff slowly fades to the background. Real life ones, at least, can balance the writing/everything else aspects a little better.
All of which might make one see it as some weird hydra to avoid, but I don't think so. It takes time and commitment: both to write and to critique and edit. And you will learn, if you want to, and grow. It may take time. You might not even realize it is happening, but you do get better. You learn how everyone does their first drafts, and definitely that no one has the same method at all. You get to see second drafts and how they improve, do your own and see how they improve.
All of which boils down to the fact that writing is a time-consuming and solitary thing, so having others to share the pain is definitely a good thing. Because the pain isn't always bad and -- the major thing -- if the group is a good group, if they're solid, they'll cheer you onto publication (if that is your goal) without resentment. Find a group that does that, and everything else isn't important.