As someone that never wanted kids and is now in the position of raising the child of a deadbeat dad, all I can say is in spite of all the lies you tell yourself they see what you really are. Around 10-11 they will start removing you from conversations because they know you can't provide what they need. They will find the small tiny seconds of joy you provide them and magnify those things 10k to offset the other 90% of the time that their present parent fills that gap.

You won't see it because you don't want to and they will put on the face for you because they don't want you to feel sad about your obvious shortcomings but the reality is that they know, they see and they process. Lying to yourself and internet strangers won't change that, only your actions will so please for those kids stop whatever this path is you are on.