so many motor bikes

Pokhara isn't small from the point of population: 600,000 people, but many live in 2-storey houses and on a large territory - the city is spread out. Anyway, the city isn't small, although not many things are here as people aren't rich - only residential houses and tiny shops (clothes, food, basic electronics, housewares).

Compared to other Asian cities - traffic very, very low, and people drive with respect.

how big cities

Kathmandu is around 1 million and its metro is 4 million. It's slightly less clean than Pokhara and much more traffic. But Kathmandu is heaven from most points compared to Indian cities. I deeply experienced Varanasi (1.5 million people) this year - it's urban hell 100%, a giant stinking ruin with failed everything (with a fantastic old time by the river - dirty as in the Medieval age and poisoned with traffic fumes and other industrial shit).

Largest cities in India have better retail - modern malls, a better choice of electronics, and much better chain grocery stores. So if you are rich and want to splurge money, choose Indian cities.