Agree with point 2. My dad is WFH 2 days a week and my mom is WFH 4 days a week. Both regularly complain about having to convert part of the living space into the workspace, and the challenges that come with having those spaces always visible and always available.

With regard to point 1 I've personally found that my work relationships have not been impacted by remote work. I still can have honest and hard conversations when needed but also able to just shoot the shit and connect with people all over the globe. I have friends in Spain, Brazil, Scotland and Italy now. However I think there's a real component of playing politics that's lost when there is no office to roam around in and jump people but in my eyes that's a good thing. And honestly that's what really bothers middle management. They've built up a career playing that game of in person politics but once they had to survive in a remote working world where ad-hoc discussions get thrown out of the window they find their usual toolbox is empty. And it drives them crazy.

I've been hearing number 3 for about 20 years. It never works out that way and if they could split the job between cheap overseas contractors and limited on site employees then most businesses would have already done so. International hiring is a good thing and great talent can be found but it's usually not the "savings" people expect it to be because the market will always adjust to demand.