Gotta realize that many of the existing suppliers started out as small suppliers.
Jameco started out small company servicing hobbyists (many corps don't consider Jameco as a viable distributor but I won't go into that).
Mouser was started by a teacher who wanted to obtain electronic components for his students.
Digikey also started out as a very small company. As their name suggests - they started by selling parts to ham radio operators. If I remember right, they first started by selling digital keyers (keyboard to ham radio codes) using small ads in ham radio magazines.
Even Arrow started out as a small store but has become corporate distributor which has eaten other distributors (e.g. Pioneer and others).
These companies have been around for 50 to almost 90 years.
GPE has only been around for over 17 years with $M's in sales and has sold to many major corporations including Japan Airlines, Intel Corp, Cisco and several others. Unlike one of the companies listed above, we don't buy parts from Chinese sellers (such as UTSource & others) or through ebay or aliexpress. We are pickey about our parts sources in an effort to keep quality at a good level. We do represent a handful of companies (some of which are not yet on website) and have more companies coming (will be adding in another major manufacturer this month). So why has GPE not become a larger company? Answer = purely motivation. I feel that we're in a big enough market size where I'm kept busy (too busy) and have no motivation to grow larger at this time.
But that overnight shipping that Arrow is offering - now that is pretty dang good.