Extra or redirect domains that redirect to a different "primary" domain do not help you by showing up in search engine results. For example, if Bevelwise were to own the domain websitemarketinggrandrapids.com which is full of keywords and redirect that domain's traffic to bevelwise.com it would not help us in search engine rankings at all. If someone were to look for the domain websitemarketinggrandrapids.com in Google, it wouldn't be found.
If search engines were to see this extra domain and try to index it, they would see that there is not any content on this domain, it just redirects to a different website. Therefore, it has no search engine value and the search engines will completely ignore it.
Back in the earlier days of the internet, people used to type in the address bar a keyword and add ".com" to try to find something. For example, someone who wanted to buy office furniture might type in "officefurniture.com" and hope they are taken to a legitimate website. People who wanted to capture this traffic would purchase these domain names and put up websites or redirect this traffic to a different site. This is sometimes called "blind" searching and it is very rare to find people doing this today. Search engines have removed the need to do blind searching.
There are a few reasons to have and keep these extra domains. The primary reason is to ensure that no one else (like your competitor) buys the domain. That is a very good reason why you would want to buy the ".net" and ".org" version of your primary domain, you wouldn't want your competitors to have those domains.
The other reason to have extra redirect domains is to capture the traffic of common misspellings of your primary domain name. For example, Google owns the domain gogle.com and if you go to that address it redirects people to the primary domain of google.com.
Outside of the two above reasons, we do not recommend to purchase additional or extra domain names unless you intend to create unique websites for those domains.