Why isn't Fight Night Round 3 backwards compatible yet?

Fight night round 4 isn't backwards compatible. I've got 360 disc and doesn't work on xbox series x. Fight night Champion is backwards compatible.

I really hope so i have been checking forums and any news I can find for 3 years now and nothing... it was super popular with me

It's unfortunately probably down to licencing rights with brands or people in the games.

Sports games and Racing games have a huge amount of real world products, characters and brands in them to make the games more authentic. The licence rights for a certain brand in the game may have expired so it would be a costly effort to bring it back if the
brand doesn't want to do it for free.

That being said, plenty of things are possible and the Backwards Compatible team are now going to start working on titles again for the Backwards Compatibility program so we may see a few new titles in the future! I would love some of the older Need for Speed
titles myself!

It's likely they just haven't gotten around to making it backwards compatible, and it might be possible it wasn't a popular game so maybe there wouldn't be much attention to it if it was made backwards compatible. It's likely the first one though, I'm
sure they might get to it eventually

It's a pity, but the retro compatibility program is paused, so there's no news on the subject. Maybe in series x you'll have more luck.

keep on rocking, my friend!