It's confusing.

For everyday usage we use a mix of the two; thus, 1998 is read as "a thousand and nine hundred and eight and ninety". So:

1998 >><<

But according to the traditional way (you hear it used in the news for example), it's read as "eight and ninety and nine hundred and a thousand". So:

1998 <<<<

However, this is so rare that many of the younger native Arabic speakers aren't even aware of it.

So in written Arabic, the digits go from least significant to most significant which means a number looks the same when written least-significant first right-to-left as it does in e.g. written English, most-significant first left-to-right.

Absolutely.

While I don't know for sure, some blame the new (mixed) way of reading numbers on the proliferation of colonial languages (English and French); i.e. people trying to mimic how the numbers are in these languages, but only doing it half way through.

The problem though is that this mixed way is used across the region, so it developing independently each time seems a bit way too improbable to be a solid cause.

Isn't arabic in general written and read from right-to-left? That way the traditional way seems very consistent.

If you think about it, arabic numerals are a right-to-left script.

2,021: one and twenty and two thousand.