Agreed. But I don't hear anyone talking about making a old style COVID vaccine that prevents infection, disease or transmission. That's what's different in this case. We don't currently have what we many of us used to think of as a vaccine.
Efficacy dropped to 60% vs Delta, and drops again to 30% vs Omicron. Boosters seem to rise back up to 90% vs Delta and 75% vs Omicron.
That's why so many people are talking about boosters: it has a measurable impact on transmission for Omicron (and Delta).
Also, IIRC Sinovac’s Coronavirus vaccine is an “old style” inactivated virus vaccine, and the J&J one is an adenovirus vector vaccine. They are not as effective as the mRNA vaccines.