I think you might be overestimating the problem.

First, Dragon Ball. During the 2010's, they released 7 games for consoles: Raging Blast 2, Ultimate Tenkaichi, Kinect, Battle of Z, Xenoverse 1 & 2, and FighterZ.Thing is, these were generally developed by other companies, such as Spike (RB2/UT/Kinect), Dimps (X1/X2), and Arc System Works (FighterZ). None of Bandai Namco's development resources went into these games.

Same applies to Naruto. You had 5 Ultimate Ninja games in the 2010's, but these were actually developed by CyberConnect2. And their One Piece games were developed by Omega Force and Ganbarion.

As for their own classic series, BN is still working on them. We had five Tales of games released on consoles during the 2010's, with Tales of Arise coming soon. We got the first numbered Ace Combat in a decade last year, Katamari Damacy got a remake in 2018, SoulCalibur VI got released the same year, the Namco Museum brand was revived a few years ago, Mr Driller got an HD remake of one of their games this year, and Digimon Survive is coming out next year. Those series pictured in the top are practically the only big ones being left dormant.

That's why they changed their name from NAMCO Bandai to BANDAI Namco.