On a 1x bike, when the chainring is not overtly worn, a large factor that drives this question is the cost relationship between the cassette and chainring.
There are plenty of bikes out there now where the cassette costs some large (relative to the past) multiple of the ring, like 6 times. Since exposing a new chain to a worn ring accelerates wear on the chain, which in turn accelerates wear on the cassette, the question (presuming a money cassette) is all about how to work the economics of the situation.
The tricky thing in practice with this question on 1x rings is that they're teeny and you're on the same one all the time so they're that much more wear-prone, but the newfangled tooth profiles are also resistant to some of the traditional chainring wear symptoms, like slipping under load.
Presuming a bike that will be around a while, a smart approach is buy the replacement chainring you'll eventually need anyway, and then use the visual comparison with the old one to guide your decision. Look at the difference in tooth profile. Is material worn off the front of the old chainring teeth? If you can see that there's really any observable change in the tooth profile and it's a typical modern 12-speed bike with a cassette that costs 5 times as much as the ring, sure replace it, the savings is probably there.
The world is currently lacking a unified rule of thumb about this question on 1x bikes, but it would not be surprising if eventually the answer just became yes, replace it. A huge piece of that is 28t and 30t etc rings wear quickly anyway, but of course with that there's also the qualifier that there's often a world of difference between brands with really good control over things like metallurgy and heat treatment with their chainrings (Shimano) and companies who chronically couldn't care less (FSA).