There's people that just don't wanna admit they were obviously wrong about SX. But must people are just lazy and/or don't pay enough attention to their consoles, and taking the time and effort to migrate isn't worthy for them.
It really depends on how often you use your Switch and what for.
Atmosphere didn't corrupt your SD, your stupidity did. It has been told, trillions of times over the years, on this community and every single other around internet, that you MUSN'T use exFAT formated cards unless you wanna lose it.
Hammering it on the floor is easier and quicker, and will deliver the exact same results: A piece of techno trash that doesn't work anymore..
That won't happen. It's true that some games released not long after HOS 11 still weren't taking advantage of the updated components inside the system, and a mere header change was enough to trick them into "thinking" they was running on the requested HOS version.
But the more time that passes after a new syster version is released, the more games will be that uses updated components. You can't just force every piece of software into running over something they aren't made to work with, specially the games developed and/or published by Nintendo.
If you don't wanna move to Atmosphere, emulate XC3 on your PC or phone. Otherwise, you simply won't be able to play it.