Opposite view here - am I gonna get mugged on a flight? Have my things stolen while I sleep? Are there homeless junkies in the airplane? No? Alright, airplane it is then.

I have taken a lot of trains... and I've never ever experienced what you're saying. Junkies or homelesses on trains? What?

What kind of train are you talking about ? Where is this ?

I've never seen any situation even remotely insecure in the years I have been taking the train regularly, either in Europe or in Asia.

Unless you conflate 'urban' train (like subways) with long distance train ? But in this case it seems like an unfair comparison : I cannot take the plane to go to work.

The stealing was rampant in Poland when I lived there, but muggings or drunken fights happen on trains here in Germany too.

Sounds like an American subway. I never had any concerns about safety on German U-bahns. Although the undercover ticket police were a surprise.

I think you raise an important point though about the safety of the environment. On some trains (mainly local), they can be no staff on at all apart from the driver. Even on larger express trains in the UK, you are likely to have 1 Train Manager and maybe someone at the buffet. They even sell a lot of alcohol and won't keep people off the train if they are drunk leading to various unsafe conditions (mainly late at night tbf)

I do wonder how the railways justify that even people who are paying first class tickets (which are really expensive) only have, at most, a single attendent for possibly 50 passengers. First class on the airplane and you might have a ratio of 1 to 10.

In Germany, they always seem to have at least two Ticket Collectors so the chance of not having your ticket checked is very low. On many services in the UK, you could get away without a ticket travelling later in the evening when many ticket barriers are left open.

Only time that happened to me was in Bulgaria / Romania, 10 years ago, on a sleeper train. Not homeless, just a grifter who we suspected paid off the conductor.