Fujianese and Cantonese have been more involved in Chinese trade with other Asians resulting in particular words and terms from those Chinese dialects being borrowed or used in other Asian languages. Similar to how some English words and terms have been borrowed or used in other languages today due to the use of English in international business. Or French words and terms in English.
One example is the word for tea:
The reason for the phonological similarity of Korean, Japanese, and Vietnamese words to Southern Chinese dialects has nothing to do with more maritime trade with those specific regions. The Western pronunciation of "tea" is indeed derived from Hokkien, but the countries of the Sinosphere were already under heavy Chinese linguistic influence from the time when Middle Chinese was still spoken across China (i.e. Tang and Song dynasties). Back then, people in the north spoke a language that sounded more similar to modern southern dialects. Cantonese and Mandarin did not yet exist, and the northern and southern dialects were far more similar than they are today. Hokkien is actually the exception since it is derived from Old Chinese instead of Middle Chinese, although it still has heavy Middle Chinese influence. How tea is pronounced across East Asia actually proves my point, since tea sounds like "cha" in every Chinese dialect except those of the Min family, and it's the same in Korean, Japanese, and Vietnamese.