I think a key thing is that not everyone is into the games. My brother quit all this kind of stuff a few years ago, even though he was actually fairly good at it, just because it wasn't his thing. Fair enough.
If people do want to learn how play well then there's probably no quick fix and some effort required. The key thing is teaching them to think the way that you do. The problem is it's quite difficult to analyse what it is about the way you play that works, and what they do that doesn't.
When you play, you are probably thinking several moves ahead, looking at threatening enemy units, objectives, various dice rolls you are going to make that will go one way or another. It's a lot of information to process. I can sometimes see exactly how a game is going to play out right from the start, especially against a less good player. Often, I plan how I want the board to look at the end of the game and work backwards from there to how I should deploy. I might then form a plan that leaves me with several potential routes to winning, or where I can force a draw with chances for me to win, or whatever. Point is, I'm looking at everything that will happen, or might happen.
A beginner might just look at one or two units at a time, thinking only about what they should do that turn, or maybe looking at some scary enemy unit. Somebody doing that is just never going to beat me, because every move they make will be completely obvious. I literally know what they are going to do before they do.
Most people are probably somewhere between the two examples. They do plan ahead but they aren't completely familiar with all the opposing units and they therefore can't be sure what their opponent is planning. I don't really know how you change the way you play, for me it was a lot of practice and reading some books about strategy. I was playing for about 8 or 9 years, since first edition, before I became really good, or found out that I was good, when I started going to tournaments at the beginning of 3rd edition.
That does give me one idea, which is that you should see if it's possible to play against some other people. It would be good practice for both of you to enter a tournament, or just join a gaming group if there is one in your area.