Abandonment is about facts - date of leaving and so on, and is not about a person's behavior, which makes it easier for some people to admit to.
Using a ground for divorce that your husband will admit to will ultimately make things much easier on you.
I served him with summons with notice, but he doesn't like the "cruel and inhuman treatment" grounds for divorce.
Can I get a divorce, even if he opposes the grounds?
My husband and his lawyer responded with a verified answer that denied all of my allegations and "strongly suggested" that I change my grounds to abandonment.