With 28 years of IT experience I can tell you that LinkedIn has become pretty essential, but I wouldn't say Catho is completely dead. The thing is, each platform attracts a different type of recruiter.
LinkedIn today is where most recruiters and bigger companies are posting jobs, especially for technical and management positions. Their algorithm favors people who are active, have recommendations, interact with content. If you've been looking for 3 months and don't have an optimized LinkedIn profile, you're definitely leaving opportunities on the table. Now, Catho still works, especially in some areas and with more traditional companies, but it's true it's become less relevant than it used to be. A lot of people seeing this in 2026 are investing in LinkedIn because it pays off more, basically.
My advice would be this: keep both updated, yeah, but dedicate more time and energy to LinkedIn. Make a decent profile there, put up a professional photo, write an about section that shows who you are, connect with people in your field. Then you keep Catho updated every once in a while, but don't stress about it. And another thing that works well is participating in discussion groups on LinkedIn, commenting on relevant stuff in your area - recruiters see that you're engaging and it's easier for you to show up in their searches. Good luck with your job hunt!