These signs and symptoms may indicate that the PSU is starting to degrade and that it should be upgraded or replaced soon. You don't want PSU problems to get out of hand, causing your PC to stop working while you're using it, or worse, damaging other, more expensive components like the processor or GPU.
Like any other computer part, you must maintain your PSU to prolong its useful life. But no matter how well you take care of it, there will come a time when it needs to be replaced. So it's better to proactively replace it before it stops working in the middle of your work or play, rather than waiting for it to die and potentially affect other components.