Being a B2B service provider myself I am in the exact same shoes. The general search volume for my main service is very low but the problem can be circumvented by going back to your Marketing persona.
There may be more than just one marketing persona.
And each marketing persona will have a number of different pain points you can focus on.
These pain points will form the basis of your pillar pages. Using the so-called skyscraper method, you can search for content that deals with these pain points in a bit more in-depth kind of way, then go back to the drawing board and do something much much better and more informative.
Next, you dissect the pillar page content into sub-topic clusters that will mean the basis of your supporting articles.
The supporting articles will each point to the pillar page via an internal link.
By having say 5 pillar pages and a min of 20 supporting articles for each pillar page you will start seeing increased traffic volumes and if done correctly, more qualified leads as well.
That's how I would approach it but you would need quite a bit of preliminary research and process in order to put your inbound/content production into overdrive and work towards results.
Reach out for a call should you need more clarification.