In case one wants to do algorithmically, here is a python snippet:
from json import load, JSONEncoder
from argparse import ArgumentParser, FileType
from re import compile
from shapely.geometry import Polygon, mapping
from shapely.ops import cascaded_union
parser = ArgumentParser(description="Group (merge) the GeoJSON ...
Or is this the intended behavior of QGIS upon export to GeoJSON and I'm thinking about this wrong?
I don't know what the intended behaviour of QGIS is, but if the intention is to write GeoJSON according its specification (https://tools.ietf.org/html/rfc7946) or just RFC7946 for short. Then yes.
Section 4 of RFC7946 tells us that
The coordinate ...
Your coordinates look like they could be in WGS 1984 - Pseudo Mercator (Web Mercator, EPSG 3857. Web maps often use Web Mercator, so it is a likely candidate), or World Mercator (EPSG 3395). In both cases, your example point would fall near the UAE - Oman border. Check to see if one of these fit your data correctly.
Some tools like projfinder and epsg.io ...
I would recommend using rioxarray.
An example of reprojecting a raster is here.
ECEF - https://epsg.io/4978
rds = rioxarray.open_rasterio("path_to_raster.tif")
crs = "EPSG:4978" # this depends on the exact projection you want to use
projected = rds.rio.reproject(crs)