Given that trading is inherently risky, if a beginner doesn't know how to manage their money but insists on trading, financial ruin could result. In this regard, we certainly need to be able to manage our finances well, and I believe this is a prerequisite for trading to minimize potential losses. In fact, I believe money management is crucial beyond trading or investing, as it can determine our lives.
In any case financial management is a key pillar for achieving goals and it's fundamental to life. It may seem simple but many people don't practice it. So don't underestimate financial management in trading.
In trading besides money management you also need risk management. Money management means being able to manage your money in trading, at least with money you can afford to lose. Risk management, on the other hand, requires knowing how to avoid risks beyond your control (such as news, black swan events, etc.). Furthermore, you need to have analytical skills when trading, such as understanding market movements and potential trends.
Everything you said is absolutely true. Financial management is paramount in undertaking any risky activity. Furthermore many beginners often overlook fundamental trading principles, such as not having a trading plan. They enter the market without a plan, simply following trending news, often referred to as FOMO. This leaves them with no clear sense of entry and exit, ultimately leading to significant risk. Planning in trading is in fact essential to financial management as the lack of a plan can lead to haphazard trading decisions and emotional oversight which can lead to losses.