In the end, it will come down to latency, usability and pricing. I do agree with you though - I'm not paying $2K+ for a macbook pro and then pay to run VSCode in the cloud -- something doesn't add up.
As for the pricing, it will likely be in the same ballpark as the non-github branded version of this exact same service (modulo any included time with a paid github subscription): https://azure.microsoft.com/en-us/pricing/details/visual-stu...
The estimated costs for full time development for one user with only one environment is ~$23.30/month.
Each environment you leave in a suspended state for a whole month would cost $6.40. OF course, if you are willing to have your filesystem wiped and rebuild each time you start and stop coding, you can destroy the environments when not in use, in which case you will probably want to create a custom dockerfile to customize the environment.