Yeah, so the generic small talk openers. This is definitely something I personally need to work on, but until then, it’s a rather large barrier to cross for socializing.

As for your other suggestions:

1. I would think most people are less willing to put effort into this than their desk decorations. What you place on your desk is for yourself to enjoy, and it gives a real window into this person’s life. A showcase as you propose is made for other people. You put things there that you think others would like to see. You’ll get very different things, and it’s harder to do, so fewer people will do it, and those who do won’t put in the same kind of effort as they would if it were for their own personal enjoyment.
2. We have these on Slack. At the start of the pandemic, we had a lot of these ideas float around on how to encourage better socialization and collaboration in an online setting. Everyone was very excited for them, but they very quickly fizzled out. Random conversations still happen and I’ll hop in on those, but they’re like conversations in a large social media platform. You exchange a few messages with a group of people, then you forget about it and never speak to them again.
3. That’s also something that was tried at my organization. It similarly had a lot of interest at the start, but very quickly died. It just seems that no one really enjoyed it as much as they thought they would.

I also just realized that a large part of socializing for me is just being physically present in the same space as another person and sharing an experience as much as it is talking. Sharing a cup of coffee with someone in silence at a coffee shop? Very enjoyable and relaxing. Doing the same over a zoom call? Awkward AF.