Two reliable standby's for me here.
I do bring 2 pairs of pants when I am out there.
LL Bean Mountain pants, which I have had so long I don't recall even buying them. It as back when the gem tones were popular. I got one of their anoraks at the same time, and it is still going strong.
Also, a pair of Field & Stream nylon pants from Dicks Sporting Goods (the legs can be unzipped for shorts) which I didn't think would last that long, however I spent 15 years climbing the 46 High Peaks, and every other outdoor activity in between and they are in remarkably good shape. I was so happy with them that about 5 years after I got them I had to get a second pair, but of course, the recipe had changed by then. Not the same by any stretch. I hate it when that happens.
I have pants from Patagonia, North Face, Kuhl and Columbia but have never had to switch from the 2 pair outlined above.
Not hi-jacking, but - don't you hate it when you have pieces of equipment that were/are your go-to's where the original was fantastic, but the "same" subsequent models were a let down? I'll start - every piece of Marmot equipment I have purchased in the last 5 years was a let down compared to the earlier models. I understand market share, margins and EBITDA, but it still pisses me off.