YES, you are.
Google and other search engines use canonical tag
To resolve cases of where duplicate content exist ... Allow me to explain the correct usage before getting into cases of why.
Say www.mywebsite.com/page1 and www.mywebsite.com?page=1 are the same because of the content management system I'm using. And I want to use the friendly URLs. This tag tells google to use www.mywebsite.com/page1 as the URL for this content; so if Google finds www.mywebsite.com?page=1 it will know that is not the best URL for this content ... use www.mywebsite.com/page1
<link rel="canonical" href="https://www.mywebsite.com/page1" />
on www.mywebsite.com?page=1 and www.mywebsite.com/page1
Some software does not recognize dynamic content (they should!)
That www.mywebsite.com?page1 and www.website.com/ are not the same. IE it wants me to put a canonical to www.mywebsite.com" on www.mywebsite.com?page1 Let them know as their program is not looking to see if the pages have the same content or different content.
Dynamic content creates different pages using a www.example.com?tag=value which are completely valid, and not the same as the www.example.com so a canonical to the www.example.com is not wanted on ?tag=value for a CMS system.
Note www.example.com?theme=dark would be the same as www.example.com (except for css) in which case a canonical would point towards the www.example.com page. But that is not the case here.
Cases of duplicate content that can be resolved by canonical
1> I have mysite.example.com publically available online and mysite.com ... because that is the setup of the example hosting company so I can access the site before I register the domain mysite.
2> I have example.com and www.example.com both providing the same content.
3> I have www.example.com and www.example.com on http and https both providing the same content. As the content does not require logging in but I want to use https for privacy of the user. So the https content is mapped to the same http content on my host.
4> I have a CMS system where www.example.com?page=canonical and www.mydomain.com/canonical are the same because the CMS system is designed not to require friendly URL but to be configured to use them if desired.
5> I have an option for users to see pages in different languages via machine translation ... This duplication may happen using Google's own tool? ... www.example.com and www.example.com?lang=spanish
6> I have a custom meme generator which passes the text via the URL but the page is the same, www.example.com/meme?text=this+shows+on+the+image. I want Google and other search engines use canonical tag
<link rel="canonical" href="https://www.example.com/meme" />
htaccess redirect can be used to prevent duplicate content being exposed in some cases.
In the first 4 cases a redirect could also solve the problem although the first one exists for a very good reason. Cases 5 and 6 would not be resolvable using a redirect. Case 4 may have very compelling reasons to exist. It may need to do so for editing the content for example.
Regardless canonical is a needed tool because cases do exist.