It's not clear to me that indie game dev was ever viable in the sense that there was a reasonable chance of making a living just from that. Some people succeeded, sure, and some still succeed. Probably a greater number reach a different kind of success, which is they make enough money and reach enough users to feel it was a worthwhile endeavor, but not nearly enough to actually make a living. But actually making a living from indie anything is always hard.
It's not clear to me that indie game dev was ever viable in the sense that there was a reasonable chance of making a living just from that. Some people succeeded, sure, and some still succeed. Probably a greater number reach a different kind of success, which is they make enough money and reach enough users to feel it was a worthwhile endeavor, but not nearly enough to actually make a living. But actually making a living from indie anything is always hard.