Shrug. Being assertive is what it's about. Any long term relationship is going to require maintenance/effort.

  you're changing yourself to suit her

Working out or wearing a suit or getting a good job or listening to a marriage counselor or acting more assertive are all examples of "changing yourself to suit her/women". Working out, for example, is the opposite of "just being yourself". Given that you will be doing this, the key is to spend time on actions that get results.

The key premise is that men are attracted to beautiful women just as women are attracted to high-status/confident/alpha men. The first half of that sentence is not controversial to articulate; the last half is where there's a conflict. According to society women should instead want men who are caring, sensitive listeners. Try that yourself and compare that to their response to an assertive leader who gives clear directions. That's all that "alpha" is; it really is an empirically large difference.