Freerider IS a good skill builder. After you can cruise through those humongous gates on there with ease you should try "Liftoff".
It's even more like really flying after you get it tuned up right and you can also see the effects that different parts have on your
"test bed" quad of choice. The trick is to play with the settings first to get the stock test quad as close to real life behavior as you
can (or at least something that you're comfortable flying and can become familiar with) so you can more easily tell the difference.
After having done that the game's physics do a good job of showing you what effect trying different props, motors, etc, have on
the flight characteristics.
FPV Freerider is definitely a great start. Although, as I noob, I wouldn't call the gates humongous. LOL. I mean to you guys with more experience they probably are, and definitely large compared to the gates in Liftoff. Depending on the course, I can usually hit the first one or two, but then it's crashing and/or circling back around time. I know with practice I'll get better, but admittedly, I've spent the majority of my time in Liftoff learning some of the tricks I see the "famous" freestyle guys doing on YT. The first time I did a power loop was purely by accident, but now they are pretty easy.
100% agree with you on the things you will learn in Liftoff. I've spent entire evenings just swapping out quads, swapping out parts, changing between 3S and 4S, etc. While there is a nice selection of parts, I wish there were more.