Other chains are way easier to interact with - for example a FE dev like myself can develop so much faster on other chains.
Saying that - that also adds a lot more vulnerability and attack surfaces where things can go wrong imo.
So oddly to interact with Bitcoin well you need a lot built around it to interact with the protocol which in a way safeguards the protocol itself.
The simplicity pulls in a lot more devs to want to start hacking on stuff. I don’t think they think about the core sound money offering of bitcoin but see these blockchains, ETH in this case, as a set of APIs to interact with.