Most of all, Taiwan is a very strategic country, because of microchips production. Considering the sanctions (Apple, Intel, AMD, Samsung, Microsoft, Lenovo, Dell, probably more, are not selling in Russia anymore) Imagine the leverage that Taiwan would give to China, and the solution it would be for Russia.
I would be very surprised that Taiwan is not next. Everything is pushing in that direction.
Edit: As other mentioned, the outcome in Ukraine is certainly a big factor, but even if Russia fails somehow, I'm not sure that it wouldn't even make it more important for China to get Taiwan...