Ah, I think I missunderstood you: I looked at scenario where I am in Inbox, then I mark messages and get the archive button as described.
But I think you have other scenario: opened the mail itself and you want to archive. Yes, then you can go to 3dot / refile / archive.
But you also can enable to show Archive button in header:
Settings / General Settings / Display / Visible Message Actions - here you can enable/disable actions, e.g Archive