Does it make sense to optimize the download speed to ideal levels if functional development and product range expansion are a priority?

I always thought that the main thing was more products and new features. But at some point, the store took a little longer to load, and I realized that something had to be done. On , I was told that speed is also about customer convenience, and they suggested optimization without compromising functions. The result exceeded expectations: the site became faster, the shopping cart opens instantly, and none of the functions were affected. Everything has been preserved and even expanded. So now I understand: speed and functionality can go together if you work with the right team.