It is much worse for boxers IMO. Just watch videos of old boxers trying to talk. Look at what happened to Ali.
Yes, I'd put it as Boxers, NFLers, Pro Wrestlers, and then MMA guys. The first two take massive hits almost weekly for decades, MMAers get saved a little bit because submissions are a big part of the training.
It's been long known in boxing, for like the past 100 years, that it's a sport that chews people up. But for the most part when a boxer's done, you didn't see them much afterward. Out of sight, out of mind.
NFLers is a newer thing, CTE has only really been though of serious there for the last 30-40 years or so. Before that, it was mostly bad backs, bad knees, etc.... that most people thought of as football injuries. Unlike boxers, you tend to see NFL guys more post retirement, so now it's out there.
Also NFLers tend to go really bad when the CTE takes hold, more interactions with police, etc.....