People choose their publicly/"semi-privately" declared sexual orientation based on what makes them happiest. If that lines up with their internal narrative, they'll be honest.

If it doesn't line up, then they'll lie, or just choose non-disclosure.

If you enjoy sex with men, but don't enjoy romantic love with men then you may very well choose to say you're 'straight'.

You might also just say you're straight if you live in a town where you believe you'll NEVER find a good man, and intend to thus stick to women for the rest of your life.

You can be out about "bi but no longer dating men" if you want to your friends, but not at work... but rumors travel slowest when as few people as possible know the truth.

After 14 years of not being able to land a single guy without going online and driving over an hour... I see little upside to telling anyone I think of myself as bisexual.

The downside to word getting out could include job loss, limited ability to change employers within my trade, losing access to certain family/social activities....

I am closeted at work. I tell most of my friends who aren't really acquaintances, but frankly I'm not sure I would out myself [even to my friends] again if I wasn't already quasi-out.

When I was with my [now ex] wife, I was out to her. That made her coming home from work one day and discovering that the porn I'd been whacking to was Russian twinks way less awkward than it would have been otherwise.