This is an accessibility feature. My deaf friend uses it because he can't hear the chimes and wants to know about notifications even if his phone is on the desk. That being said, it would be super distracting in a meeting.
I think this is mostly due to the highly polarized political climate. California is the most populous state and it's policies frequently end up spreading to other states and therefore is frequently focused on because if it's major influence. This is similar to how Texas and Florida are in the news a lot for their more conservative policies. While there are people out there who take the time to inform themselves and make their own decisions most people are only able to parrot back talking points they hear from the news or their friends. I suspect your coworker is one of those people and probably leans conservative so all he hears all day is how California's policies are making housing too expensive and it's too "woke" etc.
This person would probably be able to get away with living in the US without too many looks but this is a slang term for vagina in the UK so they might have a rough childhood there.
Either you need to expose those two services to the Internet or use a VPN. You mention vpns are inconvenient but have you checked out tailscale? The free account does your needs and it's by far the easiest one I have set up. You can also look into a cloudflare tunnel but you would need a domain name for that
Maybe they changed it then. Last time I went there I got the same stream of celeb posts the OP was talking about with nothing else.
All of that stuff exists on lemmynsfw.com. you just have to be logged into the instance to see it from their home page. Most mainstream instances are defederated from it to prevent porn from showing up in all.
I've posted here in the past week or two more than I posted on Reddit in the past 11 years. I think it's the smaller more engaged community that encourages me to do it. Comments don't just get lost in a sea of jokes and grammar bots.