They took on VC funding.

A normal "small business" doing this could run with 3 software gals, 2 genetics guys, and a CEO that handles finances and management responsibilities. A "small lifestyle business" like that could make an okay profit for all involved.

A startup, however, took $XXMM in VC funding, which included strong encouragement that "you have to hire this many people, we want at least 10x growth".

Once you hire a team of 30 people to manage your servers and a team of 180 software engineers to write your webpage, it's super hard to scale back down to a scrappy 3-5 person software team.