I wonder how big or small is your competitor website in relation to yours, if is older or have supporting pages to their products or referral links?. There are many reasons why your competitor is outperforming your product pages, perhaps receiving a duplicate and thin content warning message in the search Console is a good enough reason to be demoted.
I know that it will be a lot of work at this point trying to create content for all your products pages. You need to provide data and content that is meaningful for your intended or targeted audience. If the audience is too broad, You can star by grouping your products in a more meaningful way, group them together in categories with lots of content. Start by providing a central topic supported by the categories. Then, display more product related data that will help differentiate your pages such as SKUs, inventory levels, number of purchases, products tags and any other piece of data that will require editing just a few lines of code. Wait a few weeks and start adding more content to the best performing pages. Also, make sure your meta tags are not globally set, to avoid meta data to be duplicated as well.
I highly recommend watching this Video about thin content