Why not just ask official resource?
Sometimes projects will delete their tokenomics months or years after they successfully raised funds and token price was dumped because of bad tokenomics or sell pressure from GameFi, NFT, Metaverse gamers.
If you are a follower of one project since its beginning or before its token fall, you can know about its tokenomics. If you are late comer, you might not know about it and might not find it on their website.
One of the less advantage about these site, not every project is being listed on there. Because you need to upload or listed your project for the information, meanwhile to get the fastest resource you can just ask to their group.
It is like Coinmarketcap or Coingecko, takes time to be listed there.
I know those Token Unlock Schedule websites are smaller than Coinmarketcap and Coingecko, their information need to be double checked. It's certainly that third party websites should be used carefully and with cross checking.