I've had a Claude max plan that I've been using daily for about 6 months now. This month I decided to turn off auto-renew and moved over to Codex to try it out. There's virtually no switching costs. Of course there are some slight differences I'm noticing between the two but nothing that would keep me loyal to one over the other.

Also, Claude Code is the agentic harness with the underlying models being the anthropic ones. If it's the harness you're worried about, try out Codex or any of the open source ones like OpenCode, Pi, Goose.

This will never go away. Instead it will become more local. In the future, it's more likely that you have a model running on your computer. These companies have no moat. You don't need to worry about it going away or them charging beyond what you can pay.