With script files, you can (and should regardless of Fish usage) put a shebang at the top, like #!/bin/sh or #!/bin/bash. Then it will run with Bash as you'd expect.

I also recommend not setting Fish as your system-wide default shell (since then a missing shebang will cause it to run in Fish), but rather just have your terminal emulator start fish by default.

And yeah, outside of scripting, if I notice a command requires Bash syntax (which you can often tell from Fish's syntax highlighting turning red), then I just run bash, execute the Bash command in there and then exit back out of there.

Having said all that, I'm not trying to take away from your point. If I wasn't just joking around, I would caveat a Fish recommendation just as much.