Again... that is a fallacy. No mechanic can tell you whether or not some kind of "sleeper damage" has been done. The only way to do that would be to inspect the inside of an engine or transmission which is obviously not possible without doing a full tear-down which would not make sense... You could buy something with 50,000 miles, have a mechanic check it and say it's good, and then have a major failure 20,000 to 50,000 miles later. I'm not saying every car with 50,000 miles has "sleeper issues", but there is no way to know until you drive it for a long time. If a car has made it to 150,000 and runs like a top, then you know it would not have made it this far if it was abused. And again, it doesn't have to be exactly 50,000 and 150,000 by any means... This is just for example. And again in all seriousness, just about every car after like 1990 can easily reach 200,000 miles (toyotas will go much further) if they are taken care of. Toyotas typically had higher quality parts and would survive longer without maintenance.
If someone has the money and acknowledges this, they can do as they please, but saying "lower miles = no issues" is illogical and this should not be spread around. This is exactly why people are afraid to flush a transmission these days. "A flush ruins your transmission! Don't do it!" Etc, this nonsense spread like a wildfire. This was another fallacy. ALL transmissions need to be flushed around 40,000 to 60,000 miles. There is no such thing as a lifetime ATF. If you flush one, and it "suddenly fails or starts having issues", it was already ruined. They become ruined when you do not replace aging fluid. The flushing did not "cause the failure", it just showed you the failure that was already there.
TL;DR
Lower Miles does not always equal less issues.
Flushing a Transmission does not ruin a good transmission. (since I mentioned it above)
A good Toyota (not the cheaper ones or hybrid nonsense) will easily go 450,000 miles and beyond if you do ALL of the maintenance.
So, if you can get a cheaper one with more miles (that obviously drives well and has no issues) buy that and save money.