Ask HN: Interval for Replacing a Working Smart Phone?

Like many of us, I rely on my phone, in this case a Pixel 4a 5G, for a huge amount of things. It's function is vital to my making a living, and to be suddenly without it would be a genuine hardship.

I bought the phone three years ago in 2021, and here we are in 2024. The phone still functions properly. The battery lasts a reasonable amount (although a bit less than when new) and the only flaw I can find is that sometimes a bit of dirt or dust under the power button will cause it to boot-loop. A good hard press on the power button fixes it, and this only happens a few times a year, starting last summer.

So the question is this: Should I pre-emptively replace it? What is your interval for replacing a working smart phone, and why?