There is a difference between difficult goals and goals that take a long time to complete.
Learning a language is considered a difficult goal, but really it's just time intensive. There is nothing especially difficult or complex about building vocabulary and learning the most important grammar rules, it just takes dedication in the form of time and many repetitions.
Goals with intimidating time horizons are often the most rewarding. There are cool things you can learn in a day, a week, or a month, but they tend to be less valuable than achievements that require hundreds of hours.
There is an element of skill involved with achieving long goals. Choosing the right resources to guide you, chunking projects into actionable milestones, and adopting a patient mindset are all key parts of ensuring success.
If two people are pursuing the same goal, at the same speed, whoever has chosen the best resource to guide them will come ahead... unless they lose interest (bad goal selection) or run out of steam (usually a result of an unsustainable pace).
You become better at achieving long goals by learning how to learn. Expert learners are comfortable with befuddlement and practice good habit hygiene. Once you understand long goals aren't especially difficult, all that's left is to put in the work.
Long goals can take you places that short goals can't. Every hour you deposit into a long goal is a small bet on yourself. If you stick with your long goal to the end the payout is massive, far greater than your investment.