My marriage wasn't perfect. It was boring. BORING. That was my fault AND HER FAULT. I didn't think about it, it's not like I woke up everyday and said "my marriage is really boring." There always was stuff going on, we always went out, often as a family and not enough alone together, we had sex, we had minor differences in opinion, but we agreed with all major things. My wife was in the same marriage and did nothing about it, either. She didn't think about it, either, just woke up everyday completely happy (? - definitely not unhappy) and did it. UNTIL ... THEN ... other man dropped in her lap.
Other man did not straight on hit on her, proposition, even show he was interested. My wife would have turned her down. But other man worked through her interests, then played the game, then showed interest, then showed "look, we have so much alike, we have same interests." Other man pursued my wife very briefly, about a couple of weeks, then, after that, MY WIFE PURSUED other man. She was hooked. IT IS NOT COMPLICATED. It made her feel good, she was selfish, she didn't think I'd get caught, she took me for granted. My wife tried to delete but didn't do it right, so I found all the messages.
My wife was not planning on leaving me. She was living day to day being happy about "in love" with the other man. She never said it in so much words, but she had relegated me to "love you but not in love with you." I was her husband, the rock, dependable, faithful, and in that sense only respected me, but she was IN LOVE with the other man. Same questions you are asking, would she have left at some point in the future? What if? Like I said, all our lives are timing and circumstances to some degree.
OK, point is that your marriage is your fault AND her fault. I was always the leader and my wife was the follower, nothing ever said about that between us, but I could see that's how it was. So maybe it was more my fault about the boring marriage. I courted her, romanced her, then at some point in the marriage that didn't happen as often - career, kids, responsibilities took us away from the focus on us as much as maybe we should have. By the same token, stuff she had done special "just for me" went by the wayside a bit, also, for the same things. And I can tell you 100%, other women DID drop in my lap and I turned it down cold. But my wife, when it happened, didn't turn it down, she let the guy get in.
If you do reconcile, you should fix up the marriage, whatever is lacking or not right or "less than" it should be, fix it if you can. If you reconcile.