I think, to an extent, that’s merino wool for you, the relative fragility I mean. The downside of comfortable, fine, soft fibres is that they tend to do badly with abrasion and holing, leggings are worse because walking = friction against trousers = merino death.
I’ve used Smartwool and Icebreaker – both premium both very nice, both still fragile – Howies, ditto, Alpkit, as good as anything else I’ve used, Isobaa, same, plus some others I’ve forgotten.
Merino-polyester mixes are notably more robust ime and have the bonus of wicking and drying faster. I have no idea who makes them at present, I think Icebreaker has some options, certainly Rab and Montane used to. Personally I find pure merino gets soggy fast on mountain bikes. It’s an interesting fabric, apparently it holds a certain amount of water vapour sort of in suspension initially, but after that point, the bucket is full and it overflows into saturation. Lovely fabric for low level activities for me, not so great for high tempo/spiky on-off efforts. YMMV