Your statement is completely contradicted by the actual vaccine development. There were a LOT of Covid vaccines with different techniques and mechanisms in dev

Your statement is completely contradicted by the actual vaccine development. There were a LOT of Covid vaccines with different techniques and mechanisms in development simultaneously. Nobody knew a priori which vaccine would work so we funded the hell out of all of them. mRNA came out on top relative to all the other options at 95% plus--it wasn't even close. Sinovac (inactivated virus) was at about 50% effectiveness. Novavax (protein subunit) was about 75% effectiveness and somewhat less in the Hispanic population (not understood why). Oxford/AZ/J&J/Gamelya were about 75% but had sufficient side effect to be troublesome. And, to be fair, any of these vaccines would be in general use if we didn't have the others. The only reason why the viral vector vaccines (Oxford/AZ/J&J/Gamelaya) got pulled is because we had other options (effectively, they fail a Phase III trial since alternatives exist). Finally, mRNA vaccines are NOT easy to produce. The fact that these things have to be held at -70C or -20C shows that they are quite complex. Contrast to the Sinovac vaccine which lasts forever with standard refrigeration. The medical establishment would much rather use something like Sinovac; it's quite unfortunate that it just doesn't work that well. This is not surprising--there really wasn't any progress against other Coronavirii (common cold), either, until mRNA.