Classically. Not really. Most things were screens and buttons/plastics, maybe cart slots. The DS (which shared some components) had the EM10/EM8 inductor I think it was fail consistently enough to be notable in this.
We did recently see a clock crystal go (my first despite all these years here) and I would consider that somewhat emblematic of where we are at as we will be seeing the weird and wonderful break as we are however long on now and old electronics is no fun*.
Re CPU and RAM I don't know how useful/saleable they will be, though I would be the first to point at my previous paragraph and maybe someone will toast one with some of the overclocking people are getting into (whether you go as far as binning the RAM to see if it performs better in that scenario I leave to you). Likewise we are past the days of a new GBA being £5 at any car boot sale, yard sale, flea market, charity shop or junk shop you care to visit wherein it was mostly the nerd that could fix things that did fix things.
Most passives are potentially cooked themselves and likely have smaller versions out there today (though oversized was an issue with the clock crystal replacement, and I have had similar issues with capacitors over the years in things, though that was more because some designer either paid the serious price for something back when, pushed it harder than is ideal or... they called the capacitor plague for a reason).
External ports, and connectors are usually a fun one. Volume wheels can be tricky to both desolder and sell on as anything other than sold as seen -- they are still essentially a decades old consumer grade (none of that nice silver wear path stuff here) variable resistor with all that it entails, some mad people have managed to pull them apart and clean out).
*not particularly relevant to the GBA but a nice overview of some things you encounter in these sorts of fields
You may also enjoy
https://github.com/Zekfoo/AGZ
Reverse engineered PCB that if the PCB itself is damaged (though I question how damaged is damaged if components are worth salvaging, we have seen several die from salt water, being stored in what I can only imagine was a 100% humidity jungle and leaky batteries though).
