@Crushed23 @occhiazzurri yes same, I barely know anyone that settled down in their 20s, unless they came from a bit of an extreme background in terms of either being very wealthy or very poor.
Most people I know my age (35) aren't that interested in marriage, top of my head I can't think of anyone who got married before 35 from the men, and most are not married and have no plan to marry, just happy living with a partner 10+ years.
The single men I know are similar, lots of career focus, lots of travel, accomplishments, hobbies, sometimes time put into a PhD as well, they've had serious relationships but just at this point in time find themselves single. Granted, most of them aren't that bothered about having kids and a wedding, they aren't traditional, but also they are used to women being their absolute equals. So pros and cons depending on what someone is looking for.
Industries are advertising/media, tech, science.
I do find that law and finance perhaps attract slightly more traditional men that want to have a wife and children, get married etc, I guess it's a life goal. We had several uni friends in finance who were quite openly looking for a wife at 25!
But I don't think it's every man in London. It's a diverse city after all. I've stayed away from the 'looking for a wife' type all my life, so I wouldn't personally know many, I know more of the 30-45 and single sort.