At what point would you proactively replace all pulleys and the belt tensioner?

Lol, no worries and actually I really should take a close look at our second gen it's a 2013 coming up on a 100k miles. It never hurts to consider and look at these items. I wasn't aware that they are known or prone to go out. Sometimes something like this can be good insurance and keep the old part for a spare if not shot.

 

At 100k I did P/S fluid, brake fluid, coolant, serp belt, and replaced the two pulleys that had play (one was making a whine.)

I did keep my bottom pulley from the last two I swapped, since it was still ok (more or less). It goes in the spare parts “oh !$&@“ bin.

 

And now just this morning my daily driver 2012 Impala is making a little noise...like bearing tensioner or pulley, possibly alternator bearing....168k miles...