Here is the actual answer: The Hot 100 is a chart that measures popular singles in the United States. Because the way we have listened to music evolves over time, so has the chart's criteria.
Currently, the chart is based off of a combination of sales of individual songs (album sales do not count), streaming, and radio play. Streaming is the largest component in the chart.
Pre-streaming era, it was not possible to do this, because the chart was only based off of single sales and radio, and labels would only promote 1-2 songs at a time.
But because of streaming, even if a song isn't a "single", it can get on the chart if it has enough streams. This happens with many big artists. It is common now for major artists to have all of the songs from their album fall somewhere on the Hot 100 their debut week, when they get the most streams.
But there are only two artists who are big enough streaming forces in the US to challenge for occupying the entire Top 10 at once: Taylor Swift and Drake. Drake has come close, but he's never done it. While Iceman has 10 Top 10s, only 9 were in the Top 10 at the same time.
Taylor Swift is the only artist to occupy the entire Top 10 of the Billboard Hot 100 at once, and she's done it with her last 3 albums: Midnights, The Tortured Poets Department, and The Life of a Showgirl.
still trying to understand how an album can debut most of the songs in the top 10… if it’s based on album sales how come Madonna or Michael or Adele have never done this. If it’s based on streaming in the first week how come Bruno Mars or The Weeknd have never done this?!?