I find Ibex makes the highest quality tees (their tencel/merino/nylon shirts are incredible for hot summers) and underwear. Icebreaker also makes a variety of good stuff.
I generally look for some amount of nylon for durability, but I have a few 100% merino shirts from icebreaker that I've worn intensively for years with no problems.
I did have some pilling issues with the merino/tencel blend from ibex which is a shame. Gorgeous fabric at first; still feels luxurious.
Laundry is a bigger deal since it's wash cold and dry flat with many of these; that can be a cost, equipment, and/or lifestyle adjustment.
I'm often able to wear the same clothes many days in a row without issue.
For pants, I prefer nylon+elastane blends, but it's hard to find. Prana used to make good things here but their Brion II line was a significant drop in quality.