Bronzes (and blues) get op-ups which come with lounge access provided you notice in time. Apart from that, use of business class check-ins (particularly abroad) and priority boarding are decent perks. The point about the silver tiers and above is that they should be somewhat elite and aspirational, lounge access is a huge part of that.
It's one of those "If the Beatles reformed for a concert, what songs should they play" sort of threads really, as it's not going to happen but can lead to quite heated exchanges of opinion. And for me, I'd love to see "Yesterday", "You've got to hide your love away", and the complete side 2 of Abbey Road. Whatever those pesky bronzes say.