I agree with your point, it's not perfect. I'll give you a recent detailed exemple since you seem genuinely curious. Over the course of the meeting, the lady said: she had a kid; had previously owned a small business; had previously driven a truck for a specific company; owned a condo. In light of the personal information she had disclosed (without me asking) and of her appearance I concluded that she was most likely around 35 years old (not 25 as posted).
All these things are plausible on their own, but all of these at once at 25 is a little suspicious indeed lol. If someone's going to lie about their age they should probably avoid revealing too much about themselves because eventually it won't add up, like this case here. I mean it's not impossible but it's very unlikely.