The answer to this question isn’t that simple.
If you run your GPU on mining operation 24/7, and if you overclock it as much as possible, plus you don’t regularly clean it from dirt- yes, mining and even gaming can damage your GPU.
The main consideration when caring about your GPU health is the GPU temperature.
All three things above do increase GPU temperature, and when combined can eventually damage your hardware.
Mining 24/7 is indeed a high-performance task for your GPU. However, mining alone shouldn’t cause any problems to your GPU, as long as the coolers are working properly, and there’s ventilation in your rig.
Overclocking is something to be used sparingly, if at all. I’m not a big fan of overclocking and don’t endorse it on this website. Overclocking often and for long periods can damage your GPU regardless of mining- even if you only do gaming, or just use your PC regularly.
Cleaning your GPU vents from time to time is a great way to prolong your GPU life, whether you mine, play games or just use a PC as ordinary peoples do.