I work at Cloudflare Austin. I can't speak to this specific experience, but we have badges and a security person like every other office. It is true we don't have a reception desk in the lobby as it's a shared building.
Regarding the reception desk, it shouldn't matter if it's a shared building. Unless it's a small company (CF is not), even in shared buildings it's common to have at least one person sitting at a desk in the office suite to act as a gatekeeper and assist visitors, etc.