Use http://www.assist.org to see if the community colleges near you have coverage for the frosh/soph courses for the target major at the target UC/CSU. How good the coverage is affects how desirable doing the CC->transfer route will be.
But if he has admission to a four year school in his major, that itself is desirable in terms of not having to worry about course coverage before transfer, or whether he will be admitted as a transfer student. So if SJSU is generally suitable (including cost-wise), that is a point in its favor.
https://www.universityofcalifornia.edu/infocenter/transfers-major says that UCD design transfer admits had a 25th-75th percentile GPA range of 3.29-3.74, with an 80% admit rate in 2017.
http://www.sjsu.edu/admissions/impaction/impactionresultstransfer/index.html indicates that SJSU industrial design was extremely difficult to get into recently as a transfer, requiring a 3.70 GPA in 2018, despite being a relatively easy major to get into as a frosh, according to http://www.sjsu.edu/admissions/impaction/impactionresultsfreshmen/index.html .
Bottom line is, going to SJSU industrial design as a frosh offers more assurance in terms of being able to do the major than going to community college and taking chances with admission later.