scoring with SEO can be measured.

It comes back to yourself: in fact, if you discover that it's quicker to find information that is on your website by using google search, then your own search function of your website, and you see every time that you are ranked first, then you know you're doing a great job.

ps. try to do the same also with incognito search, as google will start to automatically propose things of your website as you click on those most times.