Some people hate chairs, it hurts spine and inhibits blood circulation in legs. Some people prefer squatting. Some people prefer sitting on bouncy big round ball.
Some people prefer standing. Some people prefer moving around. Some people prefer laying down with legs propped up.
We are humans. Not robots in a sardine can.
But the vast majority of people is fine with chairs, so it probably isn’t worth investing in other options.
The number of people that will refuse to visit your venue because you only offer chairs is … I’d say somewhere around zero.