Bitcoin traditional system is still popular as people dont have much confidence on this one ?
You can absolutely say that, as the support for lightning network from wallets and platforms are still quite low like others said. Bitcoin on-chain or "traditional" transactions are obviously still a lot more popular simply due to the fact that it's easier to do on-chain transactions. But of course, lightning is still in it's early stages and developers are still working on it, so expect it to become better as time goes.