You're incorrect, the traffic in bitcoin.com is bigger than bitcointalk.org, although the data wasn't updated since 2 years ago. But, for the other sites, then yeah bitcointalk.org is bigger than them.
what if after the update, their traffic generation can be equal to that of bitcointalk.org or even less? Like you said it hasn't been updated in the last two years and there's a lot that can happen in that space of time.
But, I'm not surprised to see bitcoin.com has bigger traffic because they're not a forum in the first place, they have many projects hence they can gather people to come into their sites.
Well that's another factor to be considered. Assuming it was just a forum and involved with other projects, will it amass this much popularity? Well, like you said, in terms of forum comparison, Bitcointalk.org has no competition.