3x6 hearing just doesn't exist new anymore. To this point, everyone thought you were talking about 2x9 gearing since 9 speed is common now.

Whoever said 18 gears is too much is nuts.
The best/only way you can get gearing to spin and get up hills(i hear those and bigger are all over Canada) is to have a triple up front with something like 28, 24, or similar teeth on the smallest ring. Then you have a cassette with a 28, 30, or 32 tooth cog.

You mention wanting above average components. They don't exist in 6speed anymore.
There is reliable 7speed. There is reliable 8 speed. There is reliable 9 speed.
But nothing for 6 speed that is above average and new.

I have a 3x7 on a touring bike with 28front and 332 rear. It works for local and regional needs.
I would imagine that if I were to try and ride thru mountains, I'd revamp everything to add more gears so I can spin in comfort and find that constantly changing sweet spot.
Less gears means less chance of finding that sweet spot.