Not understanding what words mean isn’t an unpopular opinion, you’re just wrong
Not about the first bit, that’s arguable
You definitely DO need more labels than straight, gay, and bi. For example: asexual or sapiosexual, those don’t fit into any of the 3 you listed
IDs cost money, require visits to DMVs (which conservatives work hard to shut down in poor areas, or other fuckery with their hours or such), and if you want the federal level one cost more and require more paperwork
We use the garbage and not-designed-for-this social security number for major IDing