I think it depends on what you're trying to do, and I also think the landscape is different right now than it would have been 5 years ago.
I'd actually view the browser as a more difficult market to crack than search, because there are plenty of decent free options that have not obviously succumbed to the lure of advertising revenue yet. You're also always playing a "red queen's race" with the browser market where that friction you mention with Gmail and other google properties can be used to push people away from your browser. Similarly, for email, Fastmail and Proton are both fine answers for what to do without Google, and both cover a wide enough spread of the market that I'm not really looking for alternatives (and, relatedly, running an email service _sucks_ - if you haven't hired someone with large-scale public email service experience yet, you absolutely need to do so, because it's one of the worst problems on the internet).
The search market is different - you are, to the best of my knowledge, the only actual paid search engine out there, which means you're the only one whose interests align with mine and the only one who can pursue a product strategy of actually delivering the best available information to me.
This is part of why I'm concerned about dilution of focus - as a dedicated Kagi subscriber, the reason I'm here is because you offer good search aligned with my interests, and that's why I'm going to keep paying you money. The additional products in the pipeline weren't requirements to get or keep my business, and I suspect it's the same for many of your subscribers. I trust you to run your business - you've created a great product that I'm happy to pay for, so you've earned that - but please make sure you keep the search product top of mind and make sure that's a sustainable business.