For me it comes down to trust. I'm already trusting Bitwarden with the desktop/mobile apps and the browser extension. Using rbw would require me to trust someone else with arguably my most important digital data.
As for the cost, it's both reasonable at the yearly rate and I want to support them so they can continue improving the software (still waiting for Passkeys on mobile for example).
I can't really speak to the node part, but it seems to perform well enough in my experience.
rbw is written in Rust and doesn't need premium for TOTP.