Depending on who you are, massive massive benefit. In the office it was hard to get people to stop turning up at my desk at a time convenient to them, regardless of what I was doing, to interrupt me.

training is AWFUL remote. Not even close

Definitely agree with this as a statement on how things currently ARE (in general), but they don't have to be that way. A lot of companies who struggle with this turn out to be just really bad at training in general. Previously, they got lucky; the people in need of education scrounged it by interrupting people or watching people or asking someone to metaphorically hold their hand. Companies were training by chance, rather than by design. Remote working demands a different way of training people, a different way of managing people and measuring output; a lot of companies are failing badly at this and falling back to failing less badly at it in the only way they know (i.e. everyone back to the office so we at don't suck quite so much at training and management and collaborating).