Well sir I can tell you from personal experience that this "boogeyman" as you call it does exist and it really fucks a garden up. I had to throw out all my mom's, pots, soil was a real bummer.
Now I test everything I bring in personally through tumi.
Still no proof that it was an invisible viroid.
You could have had root aphids and not known it, for instance. Entomologists have pointed out multiple possible causal factors not often considered. This is why I said there is no consensus.
Heck, your soil could have been contaminated unless you tested every component you sourced and verified directly. I've bought plenty of soil in the past that was top grade expensive hydro-store shit but also carrying multiple infestations. Source components are each subject to a myriad of contamination issues, both chemical and biological.
There is very little regulation in this industry. Don't even get me started on bottled fertilizers, PGRs, and IPM products. We've been poisoning farm soil with dubious ag products for a half century now. Agribusiness is well adept at this now.
And after all that is fine, there are still non-zero risks with just plain old bugs getting in from wherever, unless your garden is setup with BSL procedures.
I'm glad to hear you're keeping Tumi in business and they make you feel better. But if you only test once, you could still be at risk so probably best to test with them every month, for every strain, forever.