The phrase "good to see you" is commonly used as a polite and friendly greeting, but its sincerity can vary depending on the context and the person saying it. In most cases, when people say "good to see you," they mean it as a positive expression of pleasure or happiness at encountering you.
However, it's essential to consider the broader context and the person's body language and tone of voice to gauge their sincerity accurately. Sometimes, people may use this phrase as a social convention or habit without putting much thought or emotion behind it. In such cases, it may be considered more of a polite, routine greeting rather than a genuine expression of happiness.
Overall, the phrase "good to see you" can be both a meaningful expression of happiness and a polite social convention, depending on the individual and the specific situation. If someone says it with a warm smile and appears genuinely happy to meet you, then it's likely that they truly mean it. On the other hand, if it's said in a rushed or distant manner, it might be more of a customary expression rather than a heartfelt sentiment.