50 mins to declare a/c not reporting and 98 minutes to declare missing when transponder went off 2 mins after radio contact was lost - why all so slow?
These are formal declaration points. But ATC wasn't sitting on their bums doing nothing for 98 minutes.
As soon as contact is lost, procedures are followed, which includes coordinating with other ATC facilities, communicating with the airline, talking with various nearby airports, checking with military / other agencies, SAR, increasing separation from other aircraft from the area, etc.