they have. First time I went to New Zealand from Canada was in 1983. My Mom bought a year long ticket that allowed her to stop anywhere in the pacific rim in the early 70s. She sold it to someone else after 6 months and stayed in Australia for 6 months to work, then continued on her way through South East Asia.
I paid about $900 for a round the world ticket in 1986. Today they are about the same. So calculating the inflation for $900 in 1986 gives $2000 today.
So, yes the travel was possible before, but it is significantly cheaper now. Average income is also going up [1].