What type of fireplace? Wood burning? How far off the ground is the fireplace? What does the fireplace company say about it? What is code in your area?

The picture frame is there incase you change out your hearth in the future, due to repair or remodel. If, the frame gets damaged. You're just replacing and refinishing the frame. If, you just butt the ends to it. Multiple boards can be damaged.

Post some pics you do not need a hearth with a gas FP in most places and the whole picture frame look is dated for sure.

Newer construction homes have things done to them to save money not because it’s necessary the best choice .

I assume your fp is gas? If so, I wouldn't do the picture frame.

Additionally , you don’t have to do picture frame molding if you can get the tile flooring around the fireplace to be flush with the wood floor. You then frame out that section of floor with thinner pieces of your regular wood floor instead of picture frame molding . It will all look more cleaner .