is there a sensible way to check competitors keywords?

Easiest proper way is a paid tool - put the competitor's domain into Semrush or Ahrefs and look at their organic keywords list, sorted by traffic. Free route is slower: read their page titles and H2s, check their sitemap to see which pages they've built, and search your main terms to see who keeps showing up. Search Console won't help here, it only shows your own site.