There's a reason why the Switch can take a bigger dicking than the 3DS
SD cards are basically what hard drives were back in the day when you had the FAT format for Win95/98, before NTFS became a thing starting with Win2000. In that case. The TL;DR of it is that FAT had a limit of how big of a file you could stick in it, plus the way it journaled things was at risk for corruptions. When NTSC came out, it not only did things differently, but it also went "LOL fuck file sizes"
SD cards, believe it or not, have multiple different categories and have evolved greatly over the years
- SD cards are in the following capacities 4,8,16,32,64,128,256 512MB and 1GB, 2GB only.
- SDHC cards are available in the following capacities: 4, 8, 16, 32GB
- SDXC cards are available in the following capacities; 64, 128, 256, 512GB, 1TB, 2TB
- SDUC cards are available in the following capacities 4, 8, 16, 32, 64, 128TB
- SDUC memory cards must only be used with SDUC devices.
- SDXC memory cards can be used with SDXC devices and SDUC Devices.
- SDHC memory cards can be used with SDHC devices, SDXC devices and SDUC Devices
If said device was made for a specific SD card, then thats where the compatability issue comes in. Regarding the 3DS, it was stuck in SDHC hell, and couldn't be upgraded, and Nintendo even flat out said this on their support page that SDXC and above will not work on it. Since the switch is newer, it is updated for all SD formats, therefore you can give the thing all you got.