椅 is wood 木 plus 奇 for sound. Here's the surprise: ancient Chinese sat on mats — chairs arrived from Central Asia around the Tang dynasty as exotic 'barbarian beds'. A new word was needed, so wood + a sound made 椅.
椅 seats the room: 椅子 (chair — the everyday word), 轮椅 (wheelchair — 'wheel chair'). The chair quietly revolutionized China: sitting up high changed table heights, then kitchens, then banquets — food history pivots on furniture. The emperor's throne stayed a 座 or 宝座, but everyone else's dignity now rests on a humble 椅子.
A wooden 木 oddity 奇 the ancients didn't have — the CHAIR.
Chairs reached China ~1,200 years ago; before that, everyone knelt on mats — the chair changed Chinese posture forever.