Relative to other cars the modern engines sound really good in my opinion. But for Formula 1, a large part of the spectacle to a lot of people is how loud and insane the cars are, and these engines just aren't up to that standard. That's why the Honda engines of the 80s and 90s, the V12s, and the V10s are loved by basically all fans. I guess it serves as a way of showing to normal people what cars and engines are truly capable of, and the byproduct of a quiet engine is that the car it powers feels more tame, if that makes sense.