system
Given the following post, respond as if you're commenting on Reddit:
human
[Doctor Who] Why are the Weeping Angels a credible threat?

I mean there way of feeding is sending people back in time and eating the potential time energy of the left time line. Which might be a problem for normal people but anyone with access to a time machine (like the Doctor and any character we follow) shouldn't see them as a threat. 

And to stop two points that will come up certainly
> The Angels Take Manhattan 

Doesn't count the Doctor couldn't travel back to Manhattan because of the gigantic paradox the Ponds created to defeat the Angels not because of something the Angels did
>The Time of Angels 

Doesn't count as well because we were dealing with scared and starving Angels which just sucked people out of live and didn't use they normal way of feeding.
gpt
Did you watch "Blink"? They fucked shit up in that episode. They sent the doctor back in time without the tardis so he would have had to wait about 50 years to get back to the tardis, which for him may be feasible but not for his human companions.