Depends what you are developing for - if you are developing for mobile then by that standard it's significantly better.

If you are developing for web... it depends what you are writing and how you are deploying it, but it probably won't have much impact dependent on your toolchain.

For app and web development, likely it will be par or better. For system development, there could be some issues at least for the near term. Till now many homebrew core formulas are not working for apple silicon, specially related to compilers.

Not if servers are also runing ARM