Earlier quoted context omitted.
I don't understand this because I have used Firefox exclusively since it first came out and never run into broken sites. What exactly are these exotic sites you are visiting that break in Firefox? You mentioned an elusive government website but I have used many (IRS, SSA, Edu, etc...)
That's a very arrogant attitude. I'll give you one example: I sometimes can't open OpenAI API documentation due to some stupid Cloudflare captcha checks. No, on Firefox, however many times I click that checkbox, I can't go through the verification, just to read some static content. Not even if I disable adblock and tracking protection. I don't even see a checkbox at all on Chrome or Edge.
Sure, technically nobody is excluded: Just solve the captcha! Fraud heuristics are only reasonable, right?
But it's all fun only as long as your situation occurs within the 90th or 95th percentile of all data labeled "good customer". Good luck if you're out side of that...