Yet Spanish is a very expressive language, and it has no trouble expressing whatever you want using fewer vowels (note there are more than just five vowel sounds even in Spanish, it's just that variations don't have different meaning).
There's a lot of sound variation in regional dialects of Spanish, from country to country and even regions within a country. People pronounce vowels and consonants differently, and even the "accent" varies a lot (some people can seem as if they were "singing" instead of speaking, to speakers of other countries/regions).
what's cool is that regional dialects have different vowel/consonant pronunciation but the differences are almost completely consistent internally and between the dialects. Like, Peruvians pronounce anything with "y" or "ll" like an English "j" and Argentines like "sh", always. Everything maps 1 to 1.
There's a lot of sound variation in regional dialects of Spanish, from country to country and even regions within a country. People pronounce vowels and consonants differently, and even the "accent" varies a lot (some people can seem as if they were "singing" instead of speaking, to speakers of other countries/regions).