hey again!
to be perfectly honest with you, unless you're connected to the whole eco system Ie smart TV, laptops, tablets etc from Samsung, "hey google/OK Google" is a superior choice for your personal assistant!
you can install Google Lens and have literally all of Bixbys options and more to hand.
bixby is getting better but siri and Google assistants have been around longer and it shows.
bixby does a few tweaks over Google as its designed for their own phones, natural language is slightly better recognised but also the more complex settings like "hey Google, set my display to FHD" wouldn't work but with bixby it would.
if you don't use that and are happy to do it manually, then Google is better overall as it most likely ties in with all your day to day use like emails, apps, phone basic control, etc.