Depends on what you are building, but overall I'd say the friction is minimal. For a lot of apps you won't even need to care about Rust whatsoever as you just use a bunch of fairly standard JS/TS api's.
On the Rust side it's also quite nice, easy to make plugins, good api's, all the goodies.
If you do use both the bridge can cause some friction because of serialization. I have personally not had any problems with it. Also good to note that in v2 (is in beta) they are improving this.
Is there a lot of friction between the Rust core and the TypeScript frontend?