This started happening when my 09 was about 7 yo. First the driver side rear door power lock stopped functioning, then driver side front. Ran me into $600-800 each b/c they just don't do a solenoid anymore, it has to be the entire assembly. Also a brake job was coming up and the shocks were not doing all so well, so I just sold it for a downpayment on a new one.
So, yes, I would say power locks can. be an issue, it's just very unusual that it all happened at once. May be a controller issue or something like that.