I don't feel comfortable changing the PSU though unless its necessary, I have had this setup for months with no problems and low temps however you are more experienced than me.
How does the PSU damage components ?
Poor voltage regulation, filtering, indirect things like inadequate safety equipment. This is one of the most cheaply made PSUs by a major brand, only really intended for basic PCs. It uses some of the lowest-end capacitors around.
Again, you do not know you have no problems. All you know is that you haven't had an obvious disaster.
I would call replacing it necessary.
I recently had an issue with a raccoon getting into my attic. It cost me $300 for the guy to track down and trap the raccoon, another $200 for cleanup, $400 for the roof repair, and $1200 to replace the rain gutters (a section was bent, causing water damage at one spot which allowed the raccoon to get in).
I very much would have preferred to spend the $2100 on literally anything else. I could have shrugged and crossed my fingers and hoped the raccoon didn't do too much damage in the attic before it moved on elsewhere or got hit by a car. But I didn't.
Because it was necessary.
You're presumably an adult and own the PC, so the risk is yours. If you prefer to roll the dice and have to replace the GPU and/or another component earlier than you would otherwise have had to, that's your business. But I'm not going to paper over the risk when asked.