Also depends on where you live. If it's really hilly, at 30t granny might be pretty useful, especially if you'll use paniers. If it's pretty flat, a 50/34 with a 12-25/27 is probably fine

I have a triple on one of my bikes (52/42/30). Sure there's overlap, but that also means that 1) I don't have to shift between rings as much and 2) I can use a closely spaced cassette in the back. Often I can park it in the middle ring and just cruise along.

As for knees, old farts need to be careful (I'm 43). We don't recovery like we did when we were young and stupid.