Yakuza has been primarily a PlayStation exclusive since the beginning with Yakuza on PlayStation 2 in 2005. This was the case until 2013 when Yakuza 1 and 2 HD released in 2013 on Wii U in Japan. In addition to the Wii U release, you will be able to play Yakuza for the first time on the PC in August. You can now pre-order Yakuza 0 for August 2 and Yakuza Kiwami will release later this year on Steam.
Ryu Ga Gotoku Studio is considering releasing their games on many platforms. But Yakuza has been mostly a third-party PlayStation exclusive. Daisuke Sato, the game series’ director expressed his opinions. It might come to Xbox One, but unlikely Switch, he says. He believes Switch users are “used to different games.”
However, games like DOOM and Wolfenstein II doing well on Switch could be argued that ‘Yakuza failing on Wii U’ is a bad reason for not bringing it to Switch. There are almost no third-party games that sold well on Wii U. Several games like The Elder Scrolls V: Skyrim, Wolfenstein II: The New Colossus, LA Noire, Sonic Mania, and South Park: The Fractured But Whole have performed well. Some of them may not have sold gang busters and some other games may have failed, et. WWE 2K; Overall though, there are enough people playing them to want to play more games in the future.
I am fine with it being a PlayStation only game. I do own a PS4 afterall and was both excited and annoyed to hear it coming to PC. That is a big reason I bought one, anyway. None-the-less, I gave in and pre-ordered Yakuza 0 as I do not own that game on PS4 but similar to what NintendoPrime stated, comparing Yakuza on Wii U to how future sales would fare if Yakuza came to Switch will perform is silly.