Why Unreal?
It is a difficult question to answer...
There are many solutions and engines on the market (Unity 3D, Godot, Game Maker, etc) and they are all good options, but not for any project. You have to think about what game you want to make and find the option that best suits the needs of the project you want to create. If you want to be sure you must know each of the options and it becomes difficult or impossible to know if you have chosen well.
I don't have time to learn all these tools in detail and, as I always say, this is just a hobby. So... why I'm choosing Unreal if I have no idea?
Epic Games recently released Unreal Engine 5 and I've been very interested in the Nanite optimization tools, creating humans with Metahuman, and lighting with Lumen. It is an extremely powerful engine that allows you to obtain surprisingly realistic results (despite being called Unreal :D ) in a relatively short time.
Of course: it requires a powerful device to run the games made with one of the latest versions of Unreal and it could be overkill using this engine just to make 2d games or for mobile devices.
So... what project do I want to do and what features will I need? I have some idea in my head and it requires tools that allow me to express and transmit sensations to the player with a narrative that is not very complex but very showy. Unreal has tools focused on delivering spectacular results with relatively little effort and this is the main reason why I have decided to use this engine from Epic.
If it is a good or bad choice I will know it with time and experience and, in the worst case, I will have learned a lot.