The correct question is, is it worth it? When an ecommerce in PrestaShop has a TTFB time of less than 200ms, it falls within the Web Vitals metrics and loads in less than 1.4s or less. In the example images, a clean installation of PrestaShop 1.7.7.8 was used, which has a full loading time of less than 800ms, and despite this, the score is just above 80.
It is a score, not a performance index.
Can we go further? Yes, with small modifications we can reach 90, and with template customization and database optimization, we can even reach 100, but the investment in work hours and the sacrifices to be made (no Page Builder, no external JS) make the solution practically too costly for a real improvement that is almost negligible.
Like a racing car, pure performance is achieved by reducing weight as much as possible.
Just perform the same test on large ecommerces, for example Amazon.com, to notice that even they do not invest to achieve high scores in this metric, even though 0.1 ms less loading time means hundreds of thousands of euros in additional revenue for them. In fact, they invest time in Web Vitals metrics and loading times, balancing needs with performance.