Taipei is pretty crowded i would say. I have not been there, but i have been to BKK and they have those street vendors almost everywhere. Wah walking there was sometimes a night mare and it was not very clean. I dunno why when i speak to some thais they say they like it here. Sometimes the streets have so many vendors it's so crowded and traffic everywhere, u have to be alert 24/7 where got enjoyable?
To foreigners, those street vendors may appear to be haphazard, but they have some kind of system. I notice they only operate during certain times & they have to share the space with other vendors. For example along Sukhumvit those selling stuff disappear & are replaced by people selling food & drinks in the early morning.