The toilet runs on its own at night, so you swap the fill valve. A year later it’s hissing again. The kitchen faucet has needed a new cartridge too, and the pipes bang when the washer shuts off.
The easy verdict is that the toilet is cheap junk. Look at what every one of those parts has in common: each is a small valve holding back whatever pressure the street sends into the house, all day and all night.
If that pattern sounds familiar, the job worth pricing is having a plumber test the pressure and price a regulator…