Not sure what the comment in relation to 1st world operators is referring to? Can someone define it!
With regards to the Dash 8, their long term durability and life span in harsh operating environments, together with the performance far outweighs their nearest competitor in the 36, 50 and 74 seater market. Having flown for an operator with old Dash 8s and relatively new ATR-72s, from a reliably and perspective the Dash wins hands down.
Bit like comparing a Toyota Landcruiser with a Mitsubishi Pajero in the bush, the Pajero will last 15 years and the Landcruiser will do over 30 years. Same thing could be said in comparing Boeing’s to Airbuses.