This barebones nature was partly due to a large portion of the map's development taking place during March 27th and May 15th, 2020. During this time the official tools for Alyx hadn't been released and a small portion of the community (quite incredibly, might I add) created bootleg tools within days of the game's release. Leave it to the Half Life community to do something like that. Anyways, because the community had to use the bootleg tools for the time being we didn't have access to most of the assets
(and in a lot of cases all of the features, the bootleg tools didn't even have the ability to correctly compile lighting! That's why when you look back at the earliest maps made for Alyx they will be fullbright). The other reason it's not detailed is ... well .. to be frank, I was new to mapping.