What you can do is use the Troubleshooter plugin and use it to disable all of your plugins (don’t worry it is only on your end everyone else sees the same as before). Then test if your website loaded faster or slower. Another option is if you use cloudflare follow this tutorial:
My third option is to actually not use WordPress at all, there are a lot of security issues (that you need plugins to solve, hence adding to the load), high load, and other things. You can use this CMS called Publii, that generates static files and uploads them to your dashboard. You get a clean user interface and a lot of features that you normally would need plugins for. Pretty much the only reason you would need WordPress is if you want and ecommerce site (you can do that on Publii, you just need a third party ecommerce feature) or a site that needs people to create a lot of accounts. Tutorial: