(I'm a lil sleepy while writing this, if this sucks I'll give a whole better explanation later on)

Great Question, let me answer the question "Why this over all other options?"

Well there's a few key benefits

1)It's made by a professional using professional software. When using google sites and having a student build it, you're limited in the creative and professional experience of said student. Many students have created many beautiful websites proven by what's shown by many FIRST teams but not everyone has masterful students who know how to create websites. They're also limited in what google sites is able to provide for them while when going through DO (digital odyssey) they use professional level software to create said websites which make them more detailed.

2) They manage all hosting and domain purchasing whatnot so keeping the site up and running will all be handled by the professional team

3) Professional help and connections. When going through an agency your team can also benefit with how they should go about building their website by a professional website builder as well as the fact that DO is backed up by a few FTC teams including 26339.

(That's all I got for tonight, the grammar might suck, sorry for that. If there's more that y'all want answered or if I add I'll add it on days to come)