I think that this is a valid and understandable opinion to draw from this data. Here’s a quote I like to reference about situations like this from an article on “juice jacking” attacks:
“At a high level, if nobody can point to a real-world example of it actually happening in public spaces, then it’s not something that is worth stressing about for the general public,” Mike Grover, a researcher who designs offensive hacking tools and does offensive hacking research for large companies, said in an interview. “Instead, it points to viability only for targeted situations. People at risk of that, hopefully, have better defenses than a nebulous warning.”
I think that this is true and broadly applicable. Therefore, when people discuss Firefox, I will point out that there are not really any real-world examples of people being compromised because of Firefox, which is just a true statement to my knowledge.
However, like you just pointed out, that does not mean a risk doesn’t exist. People are free to make an educated decision about whether the risk is likely to affect them and choose Chromium or Firefox accordingly. Chromium is theoretically more secure against attacks.
Therefore I would not agree with the statement that Firefox users aren’t more likely to be compromised than Chromium users, but I would agree with your statement that the risk probably doesn’t matter for the average person, because despite Firefox’s risk being higher than Chromium’s, the likelihood in both cases still seems extremely small 