Why is it that it seems many older tube radios outperform most transistor models since in regards to ability to pick up remote stations clearly?
No question about it. The golden age of radio was arguably the 1930s, when a good performing and good looking radio had a place of honor in the living room, providing the family with music and other forms of entertainment, as well as news. And stations in those days were fewer and farther between than today, and used transmitters that were in most cases much lower powered than those used today.
So there was much more of an incentive in those days for manufacturers to produce well made, good looking, good performing, and good sounding AM radios than there is today. I have more than a few 1930s sets in my collection that put to shame any solid state AM radio I've ever encountered.
As in audio, what counts most is usually how well the selected design approach is implemented, and not which design approach is chosen.
Best,
-- Al