The continents lack a center. Earth's examples ... North America, South America, Africa, Australia, Asia, Europe and Antarctica ... all have a distinct 'center' around which you can draw a circle or ellipse and select most of the area of the continent. Sure bits and points stick out, but there is a distinct, roughly round 'center'.

North America: centered on the Great Plains.
South America: the Amazon bulge in the north.
Africa: The northern bulge centered on the southern Sahara.
Europe: Centered on the German-Swiss border.
... you get the idea.

Your continents are too 'stringy' - more like large irregular islands - with too many internal areas lower than sea level. (The number of places below sea level - excluding the oceans - is staggeringly few on the real Earth.)

Once you have a central continental mass, Earth seems to have mountains around one or more edges of that mass - almost at random how many sides have mountains. One algorithm for all continents (without some randomization factor) will probably have limited success at creating 'realistic' continents.

I hope that this helps.
Arthur