DreamHost servers are fast. Most my pages are 98 to 100 at pagespeed.
Your slow pages are because of how your site is constructed. WordPress is not a fast platform. Your database & backend creates your pages.This takes time (initial server response.) No changing much of that.
Having said that, there are a couple things that will help your pages load faster:
• Get rid of most of your plugins & themes. Slim it all down. Only keep what is absolutely necessary. Then get rid of still more. Remember, all this needs to load along with your pages.
• Reduce the byte size of all your images. Images are usually the slowest things to load. There are many image programs to reduce byte size, several free. This will make a huge difference.
Google’s Pagespeed (report in search console) measures your page speed primarily with FP (first paint.) The tool does not consider that many visitors are returning and load pages quicker because of previous caching. So your pages may appear to load fast for you, but for new visitors & Google’s Pagespeed, every file needs to be requested, found & displayed for the first time, every time.