Well, the Zen'Os did erase Frost when he tried to interfere from the spectator seats.
In regards to Jiren attacking the seats, my guess is that the Angels have a barrier around it, and they weren't in any actual danger.
Even Jiren isn't anywhere near powerful enough to overcome even one Angel, and they've got 12 of 'em sitting right there.
I think Goku might be at the level of the Angels right now, what with being the only non-Angel we know of to master Ultra Instinct.
That reminds me: what do you guys think of the fan theory that Goku and Vegeta are going to become an (honorary) Angel and (actual) God of Destruction, respectively? They certainly set it up that both of them are or could be at those levels of power, what with Vegeta 1-v-1ing an actual God of Destruction and Goku mastering Ultra Instinct, which seems to be an Angel technique.
edited 17th Mar '18 11:30:34 PM by PushoverMediaCritic
The idea of Vegeta being beholden to Goku for the rest of eternity is delicious.
My various fanfics.

Or more seriously: If Goku wins, could his wish be to put everything back to normal after realizing how stupid the whole ordeal was?
The only good fanboy, is a redeemed fanboy.