When is a backbulb or a rescue plant beyond saving? When the plant is conpletely brown. Until then there is a chance that new growth will develop.
This Oncidium Helen of Troy is close, but orchids are survivors. Even as brown as this plant is, there are 3 keikis forming. One is at the base and one at each of the remaining green parts of the pseudobulb.
Keikis normally get energy from the mother plant, but this one is just about used up. The trick here is to monitor the keiki daily until the last of the green is gone. It should be watered and fed, since it has its own roots.
When removing several keikis at once one option is to create a community pot to let them develop for a year. That will not work in this case since the three are at different stages of development.
The road back to blooming is a long one for this plant. If one of the keikis can be transitioned to it's own pot, it may bloom in about 3 years.