It's wrestling plus ancient traditions:

• The foot-stomping you're familiar with is done to drive away evil spirits from the earth and bring a good harvest.
• Wrestlers toss salt into the ring so as to purify it. Some choose to throw just a pinch, while others tend to go overboard.
• The highest-ranking judges carry a dagger to show their readiness to commit seppuku should they make a wrong call. In modern times, they submit their resignation instead.

Nowadays I don't follow sumo as much, the NHK is fussy about copyright and it's become quite difficult to find the broadcasts online. I'm a fan of Terunofuji, Kirishima, Ura, and Hokutofuji, though two of them have now retired.

Here's a collection of nice bouts. You can find the footage via NattoSumo's Discord server.

Nagoya 2023

• Day 3, Terunofuji vs Tobizaru
• Day 6, Hokuseiho vs Ura
• Day 10, Ura vs Kirishima
• Day 12, Ura vs Mitakeumi
• Day 13, Nishikigi vs Hakuoho

Natsu 2023

• Day 4, Ryuden vs Hokuseiho
• Day 4, Terunofuji vs Tobizaru
• Day 10, Meisei vs Hokuseiho
• Day 10, Kiribayama vs Wakamotoharu
• Day 10, Terunofuji vs Kotonowaka
• Day 14, Wakamotoharu vs Takakeisho
• Day 14, Terunofuji vs Kiribayama

Haru 2023

• Day 11, Endo vs Hoshoryu
• Day 12, Kotoshoho vs Ura
• Day 15, Kiribayama vs Daieisho