Small engines are good enough if got good FI systems to boost. Boost is the replacement for displacement.

For N/A, torque down low depends a lot on engine displacement, the bigger it is, the more punch you can get in lower rpm. The trade-off is usually in trying to get the big engine also to rev as high to achieve big power as well at the top of the rev ranges, since there would be bigger/heavier and more parts to move faster, so more difficult than getting smaller engines to rev higher. But big engines do not need to rev too high anyway since they can already generate a lot of power in lower rpms. That's the inherent advantage of big N/A engines. FI nowadays has become more and more sophisticated to substitute for displacement. In a way a car engine is like an air pump, big engines can suck more air while FI serves to supply more air. The challenge is to make it as responsive as N/A response, especially down low. So you cannot compare directly a 1.4 FI with a 1.4 N/A engine and expect the N/A to be able to match the performance of the FI one.

Any engine as long as they're designed from the beginning to be FI engine, then should be fine, regardless of the displacement. The bigger the engine, top it off with proper FI, the merrier it will be IMHO.

Can give example how thirsty they are? Like how many kms/ltr on average?

Hmm that's pretty thirsty, maybe have to be more patient/smooth with the right foot?

Haha yeah, if stuck in traffic jams, no choice, your FC will go out of the window already. My 2.5 V6 N/A also can only get best avg. of around 9km/ltr if stuck in jams.

Those average are measured with everyday trip thru Sungai Besi-Tun Razak route, so yeah not that bad.
Whoa avg speed really only 17kph?? That must be super massive jams! No wonder FC dropped so bad la.

Vios N/A engine and low power too, so nothing special there.

Good question. Theoretically might not be since smaller engines need to have forced induction and/or rev higher to achieve the same power as bigger engines. Or shall I say it's more effortless for bigger engines to make the same power, hence should not stress the engine as much as smaller engines. With forced induction also will have more parts in the car, so more things can break/wear out. But maybe with the advancement of technology in practical terms it should be reliable enough.

Maybe because the turbos are small enough that they'll already spool up fast in lower rpms. Also maybe tuned to be more rich to increase reliability of the engine.

Yeap, oversquare vs undersquare engines.