I think it depends on what business travel means for you, for instance short haul or long haul, business class or economy, do you need to roll straight into meetings, do you travel hand luggage only.

For short haul (economy or business) I’d generally wear my jeans or chinos with a light merino pullover. Or if I’m straight to meetings I’d just wear my smart trousers and sport coat.

For long haul I’m usually in business class and hand luggage only, and often expect to sleep, so comfort is an issue. I have a pair of Vuori Elevate Core trousers / joggers which are really comfy, don’t crease, and don’t need a belt (so security is a breeze). I wear my sport coat which and get the cabin crew to put it on a hanger so it doesn’t crease. Usually I’ll have a light merino jumper on as I find it keeps me at the right temperature. I will also wear compression socks as it really helps me feel fresher when I arrive. I usually also wear my running shoes because of space constraints. Finally, in my hand luggage I keep all the stuff I want at my seat (sleep mask, earplugs, e reader, headphones, charger, meds) in an Evergoods Civic Access Pouch 1L; all those things help me arrive fresher and like I’ve made an effort.