No, they do a pretty good job at getting around it. I only run into issues with Brave/Startpage, Google/DuckDuckGo/Wikipedia all work fine. And when you're fusing together multiple sources getting CAPTCHA'd is not actually a big issue, it's more so a thing to fix later.

I would say also -- if search engines are making you do CAPTCHAs every few searches, this is probably an issue with your exit node. I notice a sizable increase in CAPTCHA barriers when I'm on my VPN (most annoyingly Google/YouTube, which sometimes will serve you an infinite number of CAPTCHAs w/o letting you through).

By contrast, my SearXNG instance is making ~100 searches a day from a known good IP address (being my VPS), so rate limiting is less of a problem. You can also set up API keys for many search engines.