Something very important about that score is, it does not matter, don’t worry that much about it.
Try running the test for YouTube, it gets around 45 on mobile and 33 on desktop.
I say “around” because you get different scores on different tries.
What’s important is the actual page load speed (how much time it takes for a page to load), which can be tested with tools such as https://tools.pingdom.com
1.17 is great. Not many get below 1s, those who do are running on expensive hostings.
Every plugin you activate will add a bit to the loading speed, that’s normal. The more plugins you have the more processing your server needs to do. You can use a caching plugin to further speed up the loading ( based on the loading speed it seems like you’re already using one, but if not, consider activating one, WP Super Cache is a good one and is active on over 2 million WordPress websites ).