Why splitting t?

Hello hello,

I’m wondering why the SRS didn’t include more powers of s so that we could just commit to t without splitting it?

found a similar question asked here: Understanding PLONK

Because the polynomial commitment only supports polynomial of degree up to n. And the quotient polynomial t's degree is 3*n.

If you do not split the t polynomial into 3 pieces, then the largest circuit’s size would be n/3.