A user who returns after a while and sees the login page may be induced to believe the page is legitimate and enter their login, password and other details that will be used for improper purposes. Read more about Tabnabbing.
Unicorn startups are well known but cockroach startups often get into limelight especially when the starting funding dries up. Wikipedia definition of cockroach startup is.
Looked like a reasonable choice nevertheless reminded me of the infamous story how a startup almost went bankrupt using Firebase. I shared the story with the team & requested them to apply learnings if any from the same.