This thread seems to have ended about this time last year. In the year since Flickr continues its downward spiral under SmugMug's ownership. Groups have grown quieter, and site stability has grown far worse. This past year SmugMug asked Flickr members to extend their memberships and pay up in order to gain more cash flow. Worrisome that their budgeting has been over taxed. Worrisome that their need for future revenue will be greater since renewal membership fees will have already been spent. I have not much faith in Flickr's longevity. I was on Instagram this past year, loading from my laptop. It was not easy. But, possible. The experience there was not much to write home about, and eventually closed my account there. Happily I have found other sites like Cameraderie.org that has been loads of fun. The smaller sites have interested me. I have resumed to being happy once more with photography on the web despite Olympus Imaging's recent sale and its meaning overall. So to the thread's theme I would be for neither Flickr nor Instagram at this date: June 27, 2020 (a year since my first posting).
Sorry, have to disagree with this. My impression of flickr over the past few months has been, I would say, the polar opposite of yours.
1. The site is stable here where I live (continental Europe). In 6 months I've had the bad panda only once.
2. People are creating new groups and old, historical groups are being taken over and cleaned up. I myself have taken over six film photography group as a moderator/admin. When you refresh the message, clean up the digital cr*p and start inviting great photographers in, people feel energised, new people join and groups get back to life. It's really happening. I have to moderate queues of 20-50 photos per day in 2 of the groups I run, and most of them are GREAT medium format film photography shots by people who really know what they're doing.
3. I like what smugmug is doing to flickr personally. Not too much, not too little. I like the new group admin tools, the interface overall works for me, the new maps and tagging works. The explorer feature is being revamped. I find I'm seeing better photos in explore nowadays, the new algorithm works well. Sure there is room for improvement.
In light of all of this, I have now transitioned to pro and paid upfront for two years. Many, many people in my age group (20-45) who are also into film photography are now leaving instagram and transitioning to flickr.
The camraderie - for me, flickr was never about that. It's about people keeping well tagged, well described historical records of the development of their photo journey. Plenty of facebook groups for photographic camraderie, I find!
So no, groups in general have not 'gotten quieter' in my experience, and stability has gotten better. Flickr is a great photography platform, if perhaps a bit of an oddity in the current 'social media' world. That suits me fine.
Instagram personally I have no use for.