Apart from local AI, a serious choice is aggregated API such as new-api [0]. An API provider aggregated thousands of accounts has much better stability than a single account. It's also cheaper than the official API because of how the subscription model works, see e.g. the analysis [1].
>An API provider aggregated thousands of accounts has much better stability than a single account
Isn't this almost certainly against ToS, at least if you're using "plans" (as opposed to paying per-token)?