Few days ago, my phone suddenly shows a notification said "SD Card Unavailable". I've tried removing the SD Card and putting it back in, it wont work. I've tried searching various similar posts but doesn't work for me.
All the post I've read about told me to start my phone in safe mode and see if the card can read or not, then delete the apps or file that are causing that trouble...doesn't work (the SD Card just wont read).
Then, I also know that I can connect it to my computer and see if it's able to read the SD Card and re-format if need to, but the SD Card's File doesn't even show up in the first place.
What can I do?
(Thank you in advance)

if your sd card not even detected in windows then
sd card is dead

can I know why it's dead? lifespan reached?
I wanted to know so that I can maybe look out for a better one when I'm getting my next card.
and is the files in it, not retrievable ?