I just started using Open Router: https://openrouter.ai/

It's a service where you pay credits to use ALL the AI models available and compare them or use different models for different tasks. For example, I use ChatGPT for most, but it sucks for writing certain things. Plus, there's no monthly fee. You only pay by usage. I paid $0.03 to use Claude 3.5 this morning. You also get access to open-source models where you're not censored on particular subjects or have to deal with biases.

I can't recommend it enough. Give it a shot.