Everything has its advantages and disadvantages. Some rules of thumb are:

You can go broader, the more money you have. A broad niche, means less conversion rates because you're not able to pinpoint what exactly makes your future buyers tick.

On the other hand, going niche on a small subniche might guarantee easy market penetration but at the same time small pool of buyers.

As a rule of thumb without knowing your niche specifics is to see if your sub-niche is big enough to support your business and go for it. If not, go for something wider.

in the end it's easier going from something general to something specialized little by little, than the opposite.

Since I'm new here, i'd love to hear from you and why not give you some helpful tips on what you're trying to achieve.
My free call link is : https://clarity.fm/moneytized/moneytized
cheers,
Angel