This numbers or figures are definitely misleading because how can the site know the number of bitcoin owners when most bitcoiners are anonymous and have multiple addresses. There is the case of address reuse where one wallet can have multiple number of addresses and have bitcoin on them without actually linking them together, how does this site do it?. It is definitely wrong figures to me. All Bitcoin users can never be known due to the privacy that bitcoin provides.
Yes, mostly statistics or charts about how many users or bitcoin holders are all speculations or just an estimate of how many of them there are. The truth is that not all addresses or bitcoin wallets or addresses are owned by a different or unique individual or person, so there are no accurate numbers on how many people are being bitcoin holders. As we know, only we can identify someone in the bitcoin space by their bitcoin wallet or address, but we will never know who that person is specifically, so I don't think there are a right or accurate number of bitcoin holders. It's safe to say that there are a lot of bitcoin holders that we never know and we will never know who they are. And it's common sense; of course, there are a lot of bitcoin holders. It will be shown in the market that many transactions or trades are being made, so maybe millions, or we never know, just an estimate.
