If I play heavy games daily on my MacBook will it decrease its overall lifespan? - 1

All electronics age. Capacitors are the worst, as they have chemicals inside. Power supplies are subject to heating, same with CPUs and GPUs as the chips run hot. Using a computer will shorten its life, but storing it on a shelf is not much better.
I'm trying to replace all capacitors in a failing 2004 iMac all in one 17 inch. My Lenovo G555 laptop had 3 video chip detachments, a common problem. Now trying a new motherboard. My 2005 LCD panel from Dell had fluorescent tube failures from heat. Bought new ones. Generally no. I suppose it's possible, but not much more likely than heavy daily use of spreadsheets or databases will decrease it's overall lifespan.

Generally no. I suppose it's possible, but not much more likely than heavy daily use of spreadsheets or databases will decrease it's overall lifespan.