My favorite t-shirt is now a lightweight filson 100% wool shirt that is just as comfortable by itself at 80 deg as it is under a button up shirt at 30 deg.
And doesn't get cold when wet like cotton does.
It really does fit the "life changing" topic if you've never tried it.
https://www.filson.com/tops/210g-merino-wool-short-sleeve-cr...
> Merino wool is able to ditch the itch thanks to its fiber's smaller diameter, or being “finer”. These fibers are more flexible and softly bend when pressed against the skin and, therefore, don't itch like other wool.
https://www.smartwool.com/discover/why-merino-wool/merino-wo...
There are other wools like possum wool with similar properties that are less ambiguous in terms of ethics. Merino can be ethically sourced.
If usage of animal products is a concern, that seems hardly relevent to a question of the feel of the material. I applaud the concern, just find the "could be" to be glib and/or ignorant