afaik there are several of those offers and they are all now defunct. and as they are shabby work-arounds they do not offer anything in terms of technical group management, administration or data indexing, so it’s essentially worse than the already crappy state of facebook groups. not to mention, it’s i.e. not something your average 50+ year old dove fancier will use in place of facebook groups for their club activities. it’s unreasonable to try convince users to go from a bad solution to a worse solution. it would be better to just setup a traditional forum in that case; but everyone left those for facebook for a reason.