This is probably going to be an unpopular opinion, but if it helps, I wrote my dissertation specifically on the topic of how households gain and lose wealth (using a novel combination of income, spending, and wealth data from the Bureau of Labor Statistics).
Obviously, controlling spending is necessary. Setting a budget and understanding where your money goes is the key to that. However, I found in my research that household wealth outcomes are more related to income and avoiding spending ‘shocks’ (the bad hands you mentioned). Americans have a long tradition of privileging spending as the mechanism to wealth advancement (and again, you can’t argue it’s a bad idea to save money). However, avoiding the much maligned Starbuck’s coffees can only do so much compared to evaluating if there is a realistic opportunity to find a higher income in another field or location. Please understand, I don’t want to be horribly insensitive and say “Why don’t you just earn more money?” without understanding how incredibly difficult that is for anyone. However, if there is something hanging out there … if there is a community nearby with potentially higher wages, or some potential career change into an adjacent field, then I would say that is a priority to consider.
I would also like to clarify that I’m not saying to pay for an advancement in education! The ROI on that is significantly in doubt. If there is a way to gain education or credentials without cost, then it’s a consideration, but getting into loans is hardly a great idea.
I’ve found that family members without much financial literacy are quite scared of investing in the market. I recently helped my mom invest a modest amount of her savings in a zero fee SP500 index fund. It’s happened to do quite well in recent months, and I think it took someone doing the work to get her over the hump of being intimidated (but of course, I am not providing financial advice, I would suggest putting a very small amount in a fund just so he sees how it works).
Finally, I hope you say to your brother not to lose hope! 30 is far from too late for a good wealth outcome.