Slightly tangential, but is there a "modern" alternative to GDAL for working with raster data?

The last time I tried, stitching together tiles and cutting it to state boundaries took an inordinate amount of time (upwards of 15 minutes for 6 tiles from Landsat-7/8). Though, I'm half convinced it was because I was doing something very suboptimal..

Also, iirc, it was single threaded.