Sophie would be right.

Your fireplace's hearth looks tiny and fragile. I'm sure physically it is sturdy, but it looks entirely out of character for the rest of the fireplace and seems to have been added to accommodate the fireplace insert. It sticks out like a sore thumb unfortunately. The top tiling job looks like bathroom tiles; not a good thing in a living room.

Take a look at the lower half of the brick on the hearth. Not only does that brickwork not match the rest of the brickwork, but the grout is dark. Also noticed that those bricks aren't straight and level.

I have to agree that your best choice is to find a good mason who can cut out the old hearth and add a new one.

Gas fireplaces are consider an appliance, not a fireplace. Check the specs/info that comes with your insert. If is says “zero clearance” you don’t need a hearth.

You could then ripped it right off and cover any blemishes with trim.

It looks like the tiled hearth is teetering on that brick base. If budget allows I would remove it and the brick and then put a raised hearth across the entire brick area. Paint the brick and then a mantel shelf that spans the entire area, similar to what Beverly showed.

Little tile hearth should be removed totally. Then see if the small brick hearth looks okay as is or if it might need to be enlarged. If you paint : ) then you won't need to be concerned about matching brick colors.

Remove the tile and use a long piece of slate to make a new hearth.

A slate hearth