I have a 5-year-old and we frequently assemble wooden BRIO train tracks in a variety of configurations. As he's building out track, I'm often a few steps behind him, silently reworking the track configuration so it's not over-constrained. It typically ends up being a fun, if not simple problem solving challenge that I get to spend time with kid my at.
What I like about brio tracks is that they don't trash up the house like plastic tracks from other sets. They just look nice, feel good to the touch. The slow speed but high torque of the trains also feel like it gives "mass" (not sure how to phrase it) to the experience, unlike a lot of remote controlled toys, which go way too fast for their size but struggle with carpets, edges, ...
I played with them a lot as a kid, and I distinctly remember enjoying the sound the wheels made turning against the wood, as well as the tactile sensation of moving the train across it with my hand.
This makes me want to get a CNC machine and start spitting out train tracks! I already know when I retire in 30 years I'm gonna be one of those guys that has a train room.
I do that too. My son and his friends love building big train circuits. I love that too, but I've got a bit more eye than them for where things are under tension, and I try to correct for it.
Brio tracks are nicely designed in that altho you can combine them in myriad ways (with switches etc.), in general one of the shorter lengths of straight track does properly satisfy any gap you get.
That is to say, in the overall system, only a _small_ integer number of different straight track lengths are required.
Custom router bits do exist for the track groove profiles, which suggests that SOME folks are doing it. I've always wanted to create some custom pieces--my siblings and I growing up played with Brio far later than the expected ages, as we were all railway nerds, and frequently mis-used the degrees of freedom of track components for wildly more complicated layouts spanning rooms.
Nowadays one of my nephews ended up with lots of generic track (gifts from uncle: me) and some very specialized custom switches cast out of resin by his maternal grandfather. There are multiple ways to solve the problem!
Lidl and Ikea wooden tracks are pretty cheap and mostly compatible (you might have to file the joints a little, otherwise they can be hard to attach and detach).
Lidl & Ikea tracks give a feel of cheepnis. I haven't stopped to properly contemplate why it is so. Maybe some sanding of edges would help - Brio are much more pleasing to the touch.
A friend has 3D-printed custom duplo and lego tracks. Not sure if she's also done it for wooden railroads. I haven't but I could really use some track pieces to adjust between common length and width differences. We've got several pieces that have two sets of track next to each other, and they all have a different spacing between the two tracks. Very frustrating.
We’ve 3D printed a lot of special tracks. Crossovers and splits, bridges, etc. It was really fun, and my kid pretty much always incorporates all of them into whatever layout we’re working on.