depends on the shitcoin
some have buybacks and burn programs
some have limited supply
but you are correct in the idea that bitcoin is superior and nowadays it is really hard to find assets that beat bitcoin performance over the long run
All the buy back and burning is actually to make the coin scarce there are top shitcoins that are actually burning some coins now just to reduce supply. But one thing I have always put out is that the value of your coin comes from the usage or demand. Most of these coins do not have any use value so it is not all about the supply but what you can offer to actually make the coin to be attractive.
Bitcoin has many use case in which the limited supply is just part of the advantages of using bitcoin, many other things makes it more valuable like decentralization, store of value and many more