For self-study, it works beautifully. And the way i use it you don't need any subscriptions nor local environments/agents running etc.
I simply use google search's "AI Mode Session" in a separate tab with one per topic. That's it. No security concerns, no nothing.
The "AI Mode" is grafted onto the latest and greatest google search graph and so always uses upto date information on a topic with links to latest sources so you can always jump between AI and the sources.
Simple and Highly Effective. Just make sure that you keep your prompts specific and targeted and use Top-Down with Stepwise-Refinement methodology.
As a concrete example, i recently used it to understand the architecture of what the user was talking about here - https://news.ycombinator.com/item?id=50316022 I had the high-level view (to my satisfaction) within ten mins of back-and-forth with AI. The subject is complicated and there was no way i could have gotten the architecture without spending significant amounts of time pre-AI.