Seems like kind of an arbitrary system of ranking. just being number 1 on the billboard doesn't tell you how successful a song was. just how it compared to other songs in that same time frame.
for example with movies. Infinity War being number 1 when it released, versus Shang Chi being number 1 when it release are technically the same. but they brought in 2 very different box office numbers.
Infiniity War opened to 260 million. Shang Chi opened to 75 million. but using their logic Shang Chi was more successful because it stayed at number one for 28 days while infinity war only stayed at number 1 for 21 days.
It's fine to criticize Billboard for tons of reasons. Making a perfect ranking that covers 65 years is hard. Imagine accounting for population changes, the state of the economy, the difficulty of your era, the changing popularity of radio, the introduction of streaming, and everything else. Before you even get into the questions of studios juicing the stats with pay-for-play and shyt. I don't think Billboard #'s prove anything at all.
Point being, they clearly didn't create an arbitrary rating to prop up Elton John over Elvis or claim Janet was better than Michael. This is literally how Billboard rankings have always worked. If fellas don't like it all they have to do is stop paying attention to it, it's not like anyone is going to use this list for anything meaningful at all, posters just trying to virtue signal their fake internet militancy as always.