Crying in front of children — when sad, frustrated, or moved — is healthy modelling of emotional regulation, not failure of parenting. Apologising for it teaches children emotions are shameful. Being human with them is the better approach.
What good modelling looks like
'I'm sad about [specific thing]. I'm crying for a few minutes. I'll be okay. Sometimes adults cry too.' Brief, age-appropriate, doesn't burden the child with responsibility. Then continue the day.
Children of emotionally expressive parents (without dumping or burdening) tend to have better emotional regulation themselves. The 'never let them see you cry' framing is outdated and counter-productive.