Yes the J&J shot still works using only the spike protein. IIRC only Novavax uses traditional inoculation of using the weakened SARS-CoV-2 virus.
weakened how?
Some of the current vaccines are produced by mixing batches of SARS-CoV-2 virions with beta-Propiolactone to make them inactive.
Novavax is a protein subunit vaccine, with the spike protein only. The Chinese CoronaVac and Indian Covaxin are traditional inactivated virus vaccines.
... Does that mean that CoronaVac and Covaxin might eventually prove better than current vaccines widely available in the US?
That seems very unlikely. If a variant evolves that has significant evasion of the vaccines, then we should be able to retool the mRNA vaccines quickly. And T-cell response is more robust to antigenic drift than the antibody response, though not as well studied. See [1] for a very detailed investigation into antigenic drift and vaccine evasion.