Yes, and it's a smaller change than it sounds. Niching down means choosing who you say you're for, and your skills and services stay where they are.
Choose backward. Look at the clients who went well, name what they had in common, and turn that into markers you can recognize on a first call.
The clients who pay your rates already treat the problem as worth solving, with money assigned to it and somebody accountable for fixing it.
You stay free to say yes to anyone, at any time. Narrowing changes only who finds you, and it never fences off who you're allowed to work with.
Yes, and your marketing can only speak to one of them at a time. Serving several client types works, and one message for all of them does not.
Answer the question underneath. A client asking about industry experience wants to know you'll understand their situation fast enough to be useful.
Being thought of first requires being filed under one thing, and saying yes to all of it keeps you unfiled. Change what you say you're known for.