It is time to upgrade. If you are learning Excel 2019 to become a data analyst, you are training on a tool that is already two generations behind the work you want to do. The frustration you felt when you discovered `=UNIQUE` and dynamic arrays simply do not exist in your version is not a minor inconvenience, it is a signal that your learning path is misaligned with the profession you are pursuing.
Here is the practical reality. Excel 2021 will give you `=UNIQUE`, `=SORT`, `=FILTER`, and the dynamic array engine that makes them work. That is a meaningful step forward from 2019, and it will let you complete a much wider range of analysis tasks without resorting to clunky workarounds. But it is still a static release. Microsoft updates it once, and then it stops. If you buy 2021 today, you will face the same problem again in a few years when the industry has moved on to new functions and capabilities that your version never received.
Microsoft 365 is the only version that keeps pace with the profession. It receives continuous updates, new functions, improved performance, and AI-powered features that are rapidly becoming standard in data analysis workflows. For someone who is actively training to enter the field, the subscription cost is an investment in staying current. You are not paying for a product; you are paying for access to the evolving toolkit that employers and clients expect you to know. Excel 2019 taught you the basics. Excel 365 will teach you how the job is actually done today.
Skip 2021. Buy the Microsoft 365 subscription. The difference in cost is small, and the difference in capability is large enough that it will shape the quality of your portfolio, your confidence in interviews, and your ability to solve real problems from day one. Your skills should not expire just because your software stopped updating.