It is helpful to see what domain names are being used by companies that are growing and receiving funding. One way to do this is to read articles about fundraising on publications like TechCrunch and The Verge. There are many fundraising rounds that are shared in press releases and redistributed in industry-specific publications and not on the mainstream tech news websites I follow regularly.
To bridge this very large gap, I have found it helpful to follow two accounts on X that do a great job of uncovering funding rounds and sharing the domain names associated with these companies.