The problem with that for me is I don't get up and go to the kitchen to talk to people -- I get up and go to the kitchen to {heat up lunch, make coffee, get a g

The problem with that for me is I don't get up and go to the kitchen to talk to people -- I get up and go to the kitchen to {heat up lunch, make coffee, get a glass of water} -- and a serendipitous conversation happens as part of that. That sort of guiding activity makes the conversation lower-stakes, if it lulls you can focus on your pour-over or whatever, and it's timeboxed by the length of kitchen activity more or less, letting you get out of a conversation politely if you want. A virtual kitchen doesn't have that -- if I'm getting lunch I'm going to be in my IRL kitchen, not in the virtual one, and I'll be talking to my wife, not someone from the office. That means if I go to the virtual kitchen it will be expressly for the purpose of talking, and it's no longer a serendipitous conversation, and the dynamics become more akin to a language learning conversation group where you go to talk to people, and everyone knows how awkward those can be. (You could maybe more charitably compare it to meeting up at a bar as the OP does, but you only go to a bar to talk with people you're already close to, and getting close to people tends to happen first through repeated, unplanned serendipitous conversation. So these tools work OK for friends to keep in touch, but in my experience onboarding during COVID, not at all to get closer to coworkers.)