How long does it take to develop into a talented reviewer that other audiophiles trust? Any one have any thoughts? There are no apprenticeships for this work.
Seems like a tough job. You need audiophiles to trust you. (And that trust can be easily destroyed- just ask the Analytic Sound guys.) But you also need for manufacturers to trust you with their equipment. And you need to be a rainmaker and bring in the ad revenue. An impossible job?
Generally, trust does not emerge until a few months after you retire or die. You then have about a year of trust, then periodic moments of being remembered as a trusted resource.
Audiophiles have long, long memories; they want the reviewers they trusted when they started out to still be in circulation and are suspicious of any 'newcomers' who emerged in the intervening period. As this can sometimes include a 30 year hiatus between that first review and their latest round of review reading, the names are likely to have changed.
Generally though, what engenders trust in a reviewer is consistency. There are significant pressures today (mostly, it must be said, from the enthusiasts) to be the Audiophile Champion, trying to support an industry that receives nothing but opprobrium from without. This has meant those who write a fair review of a product are considered to be unfairly negative about that product, and more than a couple of negative reviews in relatively quick succession paint the reviewer as Benedict Arnold with a tonearm. This means that where you could - and should - be able to follow the opinions of a trusted reviewer, that now possibly needs some nuancing. Many reviewers today have two settings - default, and wow! mode. The default setting is 'this is an OK to good product, but ultimately not one that I'd choose to use in daily life.' and wow! mode is 'this really pushes my buttons and I'd be happy to use it (if I could afford it or I wasn't still paying off the product from the same category I bought last year)'. And if those 'wow!' products are consistently directed toward an audio performance you either like - or, just as significantly, intensely dislike - the reviewer's consistency is retained, and that should suggest someone trustworthy.
In great fairness, some of this comes about because we don't receive so many really dreadful products anymore. The market thins out the pack fairly quickly, and while not everything is to everyone's liking, the products that are only to the liking of the designer and their friends tend to disappear without a trace fairly rapidly. However, there's also an unfortunate side effect of audio still having a strongly review-led component to product success; we can bury a product for the least thing, and usually not something we expected. We've all accidentally killed off a good product through the merest slip of the keyboard at one time or another, and that responsibility hangs heavy.