Can only really comment for Davis stations, but 10 years service life is perhaps about par for the course, though I know of several that are still going strong at 20 and even 25 years (older model types obviously).
Given that most Davis stations are typically configured with sensors outdoors and console/logger indoors, it's the outdoor parts that tend to show cosmetic degradation and other more serious issues first. Some sensor elements have only a finite service life, especially the temp/hum sensor (maybe up to 5 years, though it varies with circumstances) and the 6410 anemometer, maybe 5 years on average though can usually be easily fixed in the current design with an inexpensive new wind speed cartridge.
Often, a station may get replaced not because of failure but because after eg 10-12 years, the technology has moved on significantly. Although the Davis model names and broad design remain the same for some years, there are many detailed enhancements to the design over time, especially for sensors. So it's commonplace for users to replace the outside sensor assembly (but not necessarily the parts indoors) after 10-15 years in order to get the latest production parts.
And, for Davis, is does depend which model you're talking about. The Vue does not have replaceable sensor elements so a serious fault usually requires replacement of the outside sensor assembly (the ISS), which is certainly available separately. The VP2 model is much more amenable to replacement of individual sensors - it costs more upfront, but the in service costs are typically less so overall it's potentially a more cost-effective station long-term. The VP2 was introduced as a general model designation in 2004/5 and there are still multiple examples of the original station design going strong (albeit with sensor repairs as required).
After-sales support is another aspect to consider. Davis, through the factory and resellers worldwide, typically provide good support for the lifetime of the station. For cheap stations support may well be much more patchy, though of course you didn't pay so much for the station in the first place.
Overall, the maxim that you get what you pay for applies to weather stations as much as many other things in life.