Yeah, most old chairs really don't have a lot of value, naturally, there are exceptions, windsors come to mind if in good condition and well built. Fine 18th century examples can command thousands but they are an exception, ditto chippendale and QA. 19th century Shaker chairs can get pricey too and of course pilgrim but, generally speaking antique chairs just dont do very well in the market.
they're not very comfortable by today's standards.
Yes, exactly. I have a 19th century Shaker tilter with a cane seat and it is an absolutely gorgeous chair, light as a feather & strong as iron but sitting in it? uhhhhhhh nooooooooooo, it's just for looking at as they say, sitting in it just isn't comfortable at all.