Not a popular opinion but I think it's often better to stay together in a relationship that has morphed into companions than uproot everything in the big gamble that the grass will be greener out there.
It's really tough out there, there's no way to sugar coat it. People who tell you differently are not being truthful.
Financially, divorce is always a huge hit that many don't recover from and impacts the children's lives significantly. Many women have found themselves in poverty after divorce or just scraping by.
Trying to find a new partner in this day and age often involves blending families, which very rarely works and is not to the benefit of the children, despite what people tell themselves.
Divorce casts a long shadow over generations and whilst adults happily tell themselves they are modelling positive and healthy relationships, often the experience of the children is very different. Shuttling between households and compromising every aspect of their lives to accommodate new partners is rarely positive. You may not get a new partner but your ex may and you'd have no control over that or who they bring into your children's lives.You just have to hope they're a decent person. Then if they go on to have kids it makes it even harder.
Kids are never really asked because most adults don't really want to know the truth, or if they do they learn to lie to hide the truth so they don't rock the boat. Children of divorce can become highly skilled at compartmentalising their lives to tell their respective parent what they want to hear.
Obviously in a domestic abuse or infidelity situation then there's no choice but to leave. But in a stale marriage it is possible to maintain stability. Life's too short to mess with your kids precious and very short childhoods.
Really think carefully what you'd be giving up on and how it would impact your kids.
If you decide to stay then really start exploring how you can make things better together.