Why does no one make advanced Flashcartds anymore? (Supercard, etc.)

[Janni9009]

just my comment about the type of flashcarts and the costs of producing them:
1. modern flashcarts with micro sd cards (everdrive, ez-flash, various n/3ds carts) all based on the same mechnism AFAIK:
load rom from sdcard (slow, but cheap) and write to RAM (fast,cheap).

Nope. Slot-1 carts all directly access SD/NAND storage, hence using a slow SD card could cause issues back in the day (and hence the EZP sucks now because it has godawful SD I/O).
Slot-2 SuperCard CF/SD did throw <32MB games into RAM just because it could iirc, but doesn't do so for anything larger either.

i also bought a spare nds flashcart recently on ali, and it only takes non-hc microsd which i do not have anmore

If this is a cart with an OGR4 sticker, it's probably actually an R4DSPro (yellow PCB) which takes SDHC just fine (actual OGR4s (green PCB) dried up a while ago).

 

[tech3475]

My guess would be that they think the market is simply too niche now and the ROI isn't there.