It's also a lot easier to point a telescope at the extremely specific points. Even if the CMB could be used as effectively as stars, you can't aim a directional telescope at the entire sky all at once. You have to pick a spot to stare at & get lucky.
Try looking out the back of your head for the planet hiding right behind you. Once you figure out that you have to turn around, the planet might not be there anymore :) We could build telescopes & point them in every direction though!
The issue seems to be one of illumination... as unlikely as it is, would it help to off a big bright bomb or two as "flashlights" to speed up the search?
Sure you can. Its inverse-square law which extinguishes the brightest flame (except of course a nova or supernova). A much nearer explosion would be much, much brighter. But you have to have some idea where to set it off.
Try looking out the back of your head for the planet hiding right behind you. Once you figure out that you have to turn around, the planet might not be there anymore :) We could build telescopes & point them in every direction though!