Periodic reminder that if you're working with woven, non-elastic fabric, there aren't many reasons¹ not to use cotton thread to sew it: it will work, it won't break and it won't rot² unless it's really bad quality thread. The time between everybody using linen thread (for linen and cotton) and when plastic thread was available wasn't that long, compared to the history of clothing, but it was still many decades, and at a time when clothing was still an expensive thing that needed to last.

¹ and other than variations “I have a TON of plastic thread and don't want to buy more” I can't think any that doesn't involve another natural fiber such as linen or silk thread.
² in your wardrobe, things may be different if you bury it in soil :)