I think H1B is for skilled workers like in tech or engineering and needs a USA company to sponsor you. L1 is for people transferring to the USA office of their company.

In my opinion, H1B is better if you're starting a new job in america, and L1 is good if you're moving to the USA from the same company.

H1b is for people in STEM and healthcare and it requires employment sponsorship. But L1 visa is for employees of international companies transferring to the branch in America.