This was probably a lot more true in the past but Linux users tend to be more privacy conscious and do things like spoof their user agent, so this is almost certainly an undercount. You basically used to have to do this to browse the web before Firefox became one of the dominant browsers.
If you spoof user agent, you will get more captchas because it won't match their other fingerprinting.
Privacy minded Linux users probably also know, spoofing your user agent is likely to increase fingerprint entropy and actually decreases privacy. It may have been true in the past, but I don't think anyone even recommends it anymore.
I don't know anyone who goes through the trouble to spoof their user agent and I know plenty Linux users.