That's the problem with just about any on-line purchase - unless you already know exactly what you want. It's a real PITA with clothes, for example, for people like me who are between a medium and a large - depending on who made it and on what day they made it! You would think 1 inch here would be exactly 1 inch there, but it clearly isn't.
They are not useless, but they
alone cannot be relied on. Published
technical specifications are not bogus - at least with the major brands promoting their genuine products. Out and out false advertising is not allowed by most governments and there are too many independent watchdog groups (including review sites) to make sure they are not bogus.
There is a big difference between published "technical specifications" and "advertising
fluff" and we, as consumers, must be able to determine the difference.
The problem is we rarely know the basis for any claims - that is, what are the test parameters? We don't know. That's how Ford, Chevy and RAM can all claim to have the best pickup truck - and they do! But best at what? And is that the criteria you need in a truck?
But those technical specs (not the fluff) are very beneficial when comparing two models from the same maker - two Samsung monitors, for example. And in your initial searches, they help you narrow down your choices.
Are there exceptions out there in this tiny world? Of course! But exceptions don't make the rule and should not be used to make a point. So once you make your choice, buy only from a reputable seller who will still be here tomorrow.
Yes, no, kinda, sorta, but not really - depending on what you do with your monitor. Again, if you are a professional photographer, or in some medical imagery scenarios, color accuracy is critical and is a matter actual measurements - not subjectivity.
So where does that leave us, as consumers? Sadly, guessing most of the time. Then with fingers crossed. Read the professional reviews and see what the professional reviewers found. Do
NOT put much faith in "user reviews"! Normal users are not professionals and typically don't have the proper test equipment or skills or demeaner to make objective or unbiased reviews. Happy people don't complain so user reviews tend to be skewed from the start. And most user reviews are completed within a day or two of receipt of the product. Many products are down-rated because the Post Office delivered it a day late, UPS delivered it next door, or the box looked like it fell off the Fed-Ex truck.
So I never pay attention to user reviews unless there are many complaining about the exact same fault with the exact same product.
After all that, you still take your chances. I bought two identical 24 inch monitors at the same time for a multi-monitor setup. They even have sequential serial numbers. Individually, their displays were gorgeous. Side by side and I could see the whites on one had a very slight blue hue compared to the other. It was so subtle, I only noticed it when I positioned an open Word document 1/2 way across both monitors. No amount of adjusting could match them up exactly. But which one was "off"? Without a professional
colorimeter, there was no way to tell. But of course, most consumers don't have access to one of those.