I think the other issue is that middle managers see that people working from home barely interact with them, which means that their middle man role is visibly unnecessary. A recipe for getting scared.
This does not have anything to do with meeting with people f2f, one can use tech tools and maintain policies. Of course having coffee with people all day is easier :)
Yep. One way forward is to move "middle" to other leaf node tasks in organisation. I have restructured a bunch of organisations towards globally distributed remote work since early 2000s. Every time: Unless I have strong investors' support I _MUST_ find a way to get the "middle" excited to move away from traditional management and coordination tasks into other things. Often this is back tech or sales where they originated. If you do it right most are happy and you get great improvements in productivity, staff retention, decision making. Do it wrong and you get mired down or sabotaged.