I see all of what is said here, and superficially how today's gadgets seem to out-do the futuristic tricorder. But do they?
Can we use a smart phone to analyze the constituents of a plant, or identify a mineral? Perform on-the-spot autopsies and diagnoses? Break down the contents of the atmosphere around us? Record an ultra-fast replay of human history and slow the images down to a stop? Though admittedly, that was achieved with Spock's technical assistance (I always did wonder exactly what his primitive memory circuit did.)
True, our modern phones can be used as position locaters...but can they be set to send distress beacons? Detectable in deep space, no less? Can the age of unknown objects be determined with a phone?
All of this, and much more I can't even remember offhand, at the touch of three butting (or dials)? With no internet to connect to, make all of this possible? And when was the last time you saw a tricorder run out of power?
I'd say the tricorder holds up to scrutiny just fine.