If the US screws up Ukraine they have another hand to play: Taiwan. This is why they are shilling the Taiwan 2023 scenario now.
There is really no going any further if they commit to Ukraine. US is running dangerously low on key weapons to launch an invasion on China even with the current rate of Ukraine war consumption.
If they do too much in Ukraine, China can further cripple their ability to make new advanced weapons by putting down an embargo on rare earths and semiconductors, as well as start reinforcing Russians in earnest.
The west's hatred and hive mind like thinking has been played against them. If NATO goes into Ukraine, a peaceful settlement that favors NATO without causing Russia to fight to the last Russian will be impossible.
If they go all in on Ukraine that will probably be the end of the US empire like the USSR empire ended with the Afghanistan invasion. They will get stuck in a forever war while China keeps soaring further away without being impacted.
The idea of invading China is mostly just an American dream. It might have been possible 2 decades ago, but today they will get as badly trashed as the USSR of 1990 would have gotten if they rolled into West Germany.
Only a suicidal US regime would try such a move.