While there are good alternatives like DuckDuckGo, Mojeek, or Ecosia, there are also ad-free alternatives, where you're not the product, like Kagi [1] or Uruky [2] (I co-founded Uruky, which is also currently and for the foreseeable future "No-AI")!
Just this morning I was helplessly looking at r/ecosia for a way to get rid of the new AI tab they've added (there's no way). Signed up for Uruky, let's see how it fares.
As of two weeks ago, you can get a couple of hours for unlimited (rate-limited) testing, just go to top up your account (or try to search) and click the PoW local and private captcha to get that.
No, but you do get the source code after 12 months of being a paying customer (signing an NDA), though we're considering releasing the code under AGPLv3 if we reach 300 monthly active accounts (we just reached 100 last week) before next year.