If you have no knowledge in SEO search engine optimization and want to get your website to rise to the top of google then yes SEO companies can be worth the money spent to hire them.
Remember though that SEO takes time so even when you hire an SEO company to get your website to rank it won't happen overnight.
Even a professional SEO company can't guarantee results overnight. SEO is a process that works gradually overtime.
Google states it can take 90 to 180 days to reach the top of google search results. So you need patience even when hiring an SEO company to optimize your website for the search engines.