The FS1000A transmitter and XY-MK-5V 433Mhz receivers are probably the cheapest options if you want to do any kind of radio transmission with Arduino. And many people assume that it will work in their application no problem.
The truth is, that it’s not that simple. The way how whose 433MHz radio modules are made puts multiple limitations: They do not add any encoding or packeting. It’s just a pure radio layer. Your Arduino code has to do the coding and decoding of the incoming signal. You can not transfer data too slowly, as the receiver will boost sensitivity and start outputting random noise on its output You can not transfer data too fast, as the signal will be lost
If you are interested, you can listed about all the details in this video