First, OEM tires are notorious for not having the best wear characteristics because the tires are designed to give good fuel economy - and they get that by sacrificing grip and/or wear - especially on Japanese cars.
Not to mention that many cars have alignment settings that aren’t good for even wear - too much camber.
So if you are buying tires from the vehicle dealer, they are likely to put the same poor wearing OE tire back on and NOT to look at the wear to see if there is an alignment problem - and even if they see an alignment problem, they are not likely to correct it (that is use a camber setting OUTSIDE the factory limits!)