From my point of view, compared to western union, bitcoin has several advantage,
compared to traditional money remittance, western union charges more,
mathematical errors have been made at many instances,
people also experienced having wrong currency exchange,
identification card and a custom transaction number is all that necessary to claim money, so more possible use by scammers.
so bitcoin is always better than western union.
I can't agree completely with you.
If you want to move your bitcoin funds to paypal, for example, or cashout in your local currency through different echangers, you will also have very high fees.
For bitcoins you need Internet and in some parts of the world people don't have Internet but have WU offices.
Recently, waiting time for bitcoin became very long, sometimes even more than 24 hours.
Through WU you can receive money in a few minutes.
So, in some cases bitcoin will be better choice but in some cases people will choose WU.