I wouldn't say that unless you notice the car doesn't keep straight as it used to, you don't need to worry about it. My Saturn tracked perfectly straight, on a straight road with no wind, I could go 75mph for literally 20+ seconds without drifting into another lane. And it chewed the FUCK out of the inside passenger side tire, until LCA and tie rod end replacement.
OP, post some details on the car, like make, model, & year. That would be helpful. This should be a requirement for posting a thread here, though I admit it's not practical. But if you're concerned about it, call around to a few shops and ask for an alignment check. At your discretion, let them know that you won't be having them align it, regardless of the results. Get a print out, compare it to factory alignment specs, post them here if you'd like, make your decision.
It's a vast conspiracy, and the complete lack of evidence is all the evidence I need.
It highly depends on what car you are driving.
Most cars should not require an alignment at this point unless you fucked up big time while driving it (driving over curbs multiple times etc).
My 07 Ford Focus I used to have required constant alignments because Ford fucked up on the setup of these cars.
Every 15k km's is what they recommended and damn did it ever need it.
Would still go through tires constantly despite proper servicing (why I got rid of it).
On the other end of the spectrum, a friend of mine had a mid 90's Mazda Protege that went a good 100k km's with no alignments. With that massive time frame it still had zero issues with uneven wear.