I also had this problem, but fortunately, I could always buy my way out of the problem better hardware and maybe one afternoon of optimization.

I finally shut down the last of my PHP side projects because of pervasive security issues and a dwindling/dead community. I recently reinstalled one of those sites on a DO droplet. Getting the right versions of everything took an entire weekend, but I eventually succeeded. The droplet had way more RAM and a faster CPU than I had access to back in the day.

But holy hell those pages still loaded so slowly. I probably didn't notice at the time because internet connections were so much slower and waiting for an HTTP page with a few images to load was normal. But those load times would be absolutely unacceptable today.