Interested in hearing others take on this. Either from experience or current situation.
I've heard both side of this.
Build something that solves your needs first and you'll always have a customer.
or...
Build something that solves a big important problem even if it's not your own.
I opted to build something that solves my own problem and share that solution with the world. Knowing I'm likely not the only one with the problem. I also however am not interested in running a multi multi million dollar company so I'm not worried about solving big problems for mass markets.

I think this is true to some existent. However, the difference is whether your own personal use case is representative of a group of consumers. If there aren't many buyers like you out there, then this approach won't work unless you can create a high ticket product.