The streamer is built from the ground up internally to isolate electro magnetic fields, vibration, and condition and provide clean quiet power. Also the CPU and circuit is made to not wonder off and do non-essential stuff. You cannot do this stuff after the fact. You can improve the sound from a computer, but a good purpose built streamer starts with too many advantages to be competitive with a PC. That said, you can’t expect a $20 or $200 streamer to be competitive. streamers get better as the design, parts and components are improved. I am not an expert on the technology, but am an expert in the way they sound.
My cheap streamers were significantly out performed by my first high end $2,500 streamer (note the cost of a Laptop), this was outperformed by my $4,500 streamer (not subtle), this was outperformed by my $10K streamer… but the biggest jump in sound quality was to my $22K streamer. Of course you have to have the associated equipment to realize these gains. I would imagine you could hear the difference between a $10K and $20K streamer on a $1,000 system… but it would be a foolish investment. You want to deploy your across all your components in a way to maximize sound quality.
And before anyone jumps on the “cost isn’t a good guide” I am assuming you are buying the best for that amount of money not just randomly buying on price. I like to give people the credit in caring about how they spend there money and do the work. All of my purchases have been meticulously research an compared… and under those circumstances the cost was highly correlated with price.