> IMO turbo cars are very dirty "under boost". Often turbo cars are tuned rich (more fuel) to prevent detonation. They can have great emissions just cruising around, but the second you build boost....not so much.
Most modern turbocharged cars run direct injection and high metal loading catalysts and target lambda=1 even under boost, which causes tuners' brains to melt upon seeing the factory tune.
Detonation is controlled by less aggressive timing and various direct injection strategies, while high EGTs and NOx are addressed by the high precious metal loading in the cat.
After an extended amount of time in full load these cars will eventually enter catalyst or turbine protection and start dropping lambda, but this is uncommon amongst daily driving conditions (even under boost).
The rest is true, I agree - there is no practical way that a part which spins at 180,000rpm and pressurizes the intake manifold (introducing a ton of complexity to the PCV system, engine packaging, and everything else along the way) is going to be as reliable as a naturally aspirated engine at the same cost. But, if this comes with enough advantages to make the cost expenditure worth it, they can be made reliable.