What do we think of gender neutral / gendered language?

[BolloxtoGender]

they instead of he/she (I'm not keen on this unless the sex is unknown, or is someone's preferred pronoun)
distinguished guests instead of ladies and gentlemen (not keen either)
Everyone, People/person (glossing over, bland)
Actor vs Actor/Actress (not keen , as pretending that 'Actor' is gender neutral when it is not)
Manhour, mankind to mean generically - I don't mind, and what's the alternative anyway?

Does gender neutral language effectively make females even more invisible? When means that women's achievements and presence, for example, are not recognised.

Thoughts?

My neighbour used to work for the council going down manholes to deal with sewage. He said he’d call them person-holes when women started going down them!