The vast majority of deaths by train involve "trespassers", which is code for "dimwits who bypassed crossing gates and got smashed by the train that couldn't stop". Usually not even the train drivers are injured, much less the passengers.
But airplanes are very safe - perhaps mostly because it's hard for idiots to drive in front of them.
- Most people don't fly often enough to justify Statistics significance (I for one only flied maybe less than 10 flights in my whole life)
- One flight is going to cover a huge amount of mileage anyway
Edit: Just realized that issue 1 is not an issue, we are going to do an average here anyway, so not individual.
Is there actual reason to think they are less safe per hour of time being spend in them as OP claimed?
First, you are correct about trespassers. But even if you only consider passengers, planes are still safer per passenger-mile than trains.
Second, commercial planes are very safe. Private planes... not in the same league.
In contrast, the United States saw 125,700 preventable deaths in the home in 2023.[3] The country had a population of 336,806,231 people back then.[4] This means a probability of approx 1:2,679 (0.037 %).
[1] ATAG Aviation Beyond Borders 2024
[2] ICAO Safety Report 2024 Edition
[3] National Safety Council (NSC) Injury Facts
[4] World Bank
By these metrics commercial flying isn't as safe as you think.
It's code for suicide. The remainder are as you described.
Furthest you can go in a straight land on land is about 7000 miles :).