Is it possible to guarantee anonymity in Bitcoin?
No, theoretically there's always risk no matter which method you use. For example, certain mixer could be honeypot set by government.
But here comes the most intriguing question: is the level of privacy provided by these tools enough to protect our identities and activities in the digital world?
Protect from whom? Random stranger/stalker on internet? Blockchain analysis company? Triple digit agency?
Or should we be focusing on developing new solutions and improvements to further safeguard our privacy in the Bitcoin ecosystem?
With current Bitcoin ecosystem where new improvement is optional to use, IMO any solution won't bring very major improvement towards privacy.