Well, the transaction is fast unlike other payment processor, what we could say that is no longer fast is the conirmation of transactions which takes longer than usual these days.
No, it does not. It requires the exact same amount of time that it always did, 10 minutes on average per confirmation.
BTC transaction time now is even ~ 28 hours. Of course it is a long time, for example bank payments are faster.
Wrong. Transaction time is: ~1-3 seconds. Confirmation time is: ~10 Minutes.
that case are rare , i can say it could happened 1 from 100,000 transaction. it's happened to me too sometimes.
No. There is no chance of this happening if you know how to properly use Bitcoin (which includes both knowing what causes these things and knowing how to avoid them). The chance for a confirmation time of 28 hours for a proper transaction (assuming rational size, and adequate fee) is 0.
bitcoin just need to make it consistent confirming the transaction in 1 conf only
This sentence does not make sense. Maybe you've meant after 1 block?