German isn't an obvious choice in Canada. It's not official, it's not the language of a large local community in most cities, and French and Spanish both have broader day-to-day use. It's worth learning for narrower and more specific reasons, and whether they apply to you is a fairly answerable question.
Where it pays professionally
Engineering and manufacturing. German-headquartered firms have a substantial presence in Canadian industry, particularly in automotive parts, industrial machinery and chemicals. If you work in a supply chain that terminates in Germany, the language appears in your working life.
Research and academia. Germany is a major research economy with well-funded institutions, significant English-language graduate provision, and strong Canadian academic links. German isn't usually required to study there, and it matters a great deal for living there and for archival work in several fields.
Specific disciplines. Philosophy, theology, musicology, art history, classics and parts of history still have substantial literature that isn't translated. If you're working at that level, German isn't optional.
Trade and professional services. Germany is among Canada's larger trading partners outside North America, and the relevance follows the same logic as any trade language — it's about whether your counterparts would rather be speaking it.
Where it doesn't
If you want a language for daily use in a Canadian city, German isn't it. French is the one with institutional weight here, and Spanish has the larger community presence and the larger travel application.
Nobody should learn German for general Canadian employability, and anyone claiming otherwise is selling lessons.
The other reasons, which are legitimate
Moving there. Germany, Austria and Switzerland all run significant skilled-immigration routes, and German transforms the experience of living in any of them even where the job is in English.
Family and heritage. Canada has long-established German-speaking communities and a great many people with family connection to them.
Reading. German opens a literature, a philosophical tradition and a music culture that translation only partly delivers.
It's interesting. A perfectly good reason that people feel obliged to apologise for. If you find the language satisfying, that will sustain more study than a career argument you don't believe.
What's achievable from Canada
More than people assume. The Goethe-Institut has a Canadian presence, Goethe exams are sittable here, and online instruction removes the main obstacle, which was ever finding a good teacher nearby.
What you won't get passively is immersion. There's no German-speaking environment around you, so the practice has to be arranged deliberately — which is a scheduling problem rather than a geographic one.
The test
Does German appear in your work, your study, your family, or a place you intend to live? If yes, it's worth it, and the case is specific rather than general. If no, learn it because you want to — and skip the justification.