I battled plantar and related issues for 20 years. I've had every problem under the sun, and seen every possible type of doctor for them (from psychic to podiatrist to orthopedic, to endocrinologist, and neurologists... Okay, no psychics), and had every treatment imaginable, short of surgery. I even spent a decade on the couch because I could barely walk...training (even easy biking) was impossible.

I agree with Q as a general approach to managing shoes. Have a rotation of old and new shoes. When you come home from a run and your feet feel like shit, removes those shoes from the rotation, and add another new pair.

That said, if your feet already feel like crap, it's probably past time to replace the shoes. Shoes don't have a "fixed" life. It's all about what your body can handle. If they don't feel good, it's time to switch.

I used to only get 300-350(max) miles out of a pair before I'd start having issues somewhere (Achilles or other ankle tendons, or plantar, or neuroma, etc). I'm up to 500+ per pair now... Which I attribute to stronger stabilizers (core, hip, leg, and ankle). But, I don't toss them on a fixed schedule... I do like I said above, whenever I start to feel it in my joints post run, I drop that pair. If I'm doing a lot of hard running, maybe it's 430mi.... If I'm just running easy... Maybe 550mi.

Try the new shoes for a run, if you feel better after switching don't go back.

Eta: it also helps to have an inventory of shoes. I have two pairs in rotation, right now... And three pairs in the closet. That's probably enough for all of 2020. I tend to buy them online (closeouts and such) the last two pair I got for 1/3rd the online price of the "current model". Having that inventory makes it simple to switch immediately. Buying last year's model at a low cost makes me not even think about trying to stretch it out a outtle more.