Locally-run LLMs are very cool, but I think we have some way to go for smartphone performance to make datacenter-run (or beefy personal workstation for privacy!) ones obsolete.

Until then, I also really like the idea of making chatbots accessible via instant messengers. I find myself using the one in WhatsApp quite a lot these days, just because it's conveniently available on multiple platforms (with my history synchronized) and I can tag it in when chatting with friends. It also works on flights with zero-rated messaging.