But at least when you buy something like BTC, you know which one is which, it's a fork or not, a scam or not, per se - it's like saying you are afraid of buying Bitcoin Cash instead of real BTC due to the dealers (the exchanges and such), which is not happening if you are vigillant enough.
If you are buying Bitcoin, the person buys Bitcoin, and if you are buying Bitcoin Cash or any other fork, you buy those ones. The differences are very clear; you don't even need any special skill to differentiate one from the other. Price is one of the major factors and many others which could easily be identified.
The worst that comes close to what could be used as a convincing one is offering to buy shitcoins, which are claimed to be Bitcoin pegged under different networks like Binance Smart smart chain.
Fortunately, not as many people in the space are stupid enough to buy something offered as BTC but in reality, not so much so.
These days, it's very easy to proof check such things in a minute or two.