You could hire a developer to edit your current websites and build any new sites from scratch, but the cost of doing that just isn’t reasonable. We’re talking thousands of dollars of ongoing expenses especially if you’re building new websites.
You could optimize the websites on your own. As an example, WordPress has tons of plugins to help with page speed, but you run into compatibility and security issues, not to mention countless hours of work. Even after all of that, your site may not run as fast as you need it to.