I'm disagreeing with your link, that's my point.
When Kunark was current, LOIO was always packed, and all the leveling I did there went very quickly. And the reason was known, and it was a ZEM bonus. At that time, starter zones (zones expected to be used by brand new chars) had a generous ZEM bonus. This was a known thing. LOIO was one of those zones. It was also one of the very few starter zones which had content up into the 20s (Sarnak fort area).
The link you referenced is from 2013, so some 12-13 years later. I have no idea what the LOIO ZEM is in modern times, but, as I said, when it was current content, and immediately after, it had a bonus ZEM (i.e you leveled faster there).
Tatanka Wolfdancer, 106 Wood Elf Druid, 7 x 300+ Master Artisan, 7 maxed trophies :)
Anaceup Mysleeves, 105 Erudite Mage, 2 x 300 Master Artisan
Snookims Whinslow, 105 Erudite Enchanter, 2 x 300 Master Artisan
<Inisfree>, Tunare (Seventh Hammer!)
Tatankaa (95 Inquis)/Urkell (38 Conj)/ Seanthornton (24 Pally), <Inisfree> Freeport server (some other server now)