You mentioned videos being long. Why not watch those, or a lets play?

The beginner videos are usually supposed to be watched as you're playing the game, meaning that say an almost hour video needs to be paused. By the end of it, it would likely almost be 2 hours. That doesn't even account that one game of Stellaris lasts much longer than 2 hours alone.

You can see someone who knows the game play it, and find out if it's something you'd be into.

This is weird, and may seem as a cop-out, but unless the game is from a really familiar genre/series (Shooters or RPGS) then watching someone play it doesn't really help. I have to play it myself to know. A few games I could say this occurred with me is Hollow Knight, Monster Hunter, Dead Cells, and Slay The Spire. I was able to play them through game-sharing then I had a proper grasp of them, but I'm not able to do with Stellaris and the game doesn't seem to have a demo either.