It depends on what purpose you are using the polygons. In an online map you need to simplify way down. Consider these Colorado maps at two different zoom levels:

https://maps.app.goo.gl/JH93ko96QcoLXuBJ9

https://maps.app.goo.gl/au53iTnsmNdFuEZV8

Even the one zoomed in on the state appears to use maybe 15-20 vertices max.

In the second one, if I squint real hard I can just barely make out one slight dogleg on the western border and one on the south. And that is partly because I knew to look for them in the zoomed-in map.

If we use, say, the Census TIGER/Line boundary definitions for the states, we are probably talking about hundreds of thousands of vertices, perhaps millions. You won't be using those in an online map without simplifying.