I believe, in an era ruled by CoinMarketCap/CoinGecko/Nomics, Preev.com was still popular because of certain reasons...
1. Simple interface
2. Dedicated domain
3. No advertisement
The first option, given by you, can be still be considered as a dedicated subdomain. But, the second option simply does not cut it. If I include that, I'll need to include many others like
https://nomics.com/markets/btc-bitcoin/usd-united-states-dollar etc. In any case, if more people mentions
https://preecs.coolstorage.org, I'll include it in the poll.
In another
post on BitcoinTalk, I came across two more domains, running the same script. These, I believe, can become alternative to Preev.com. So, I am including those as well...