Why does this page list the radicals for 等 as 竹, 士, and 寸 when the word appears to use 土?
Things that contain「寺」may be written with「士」in the Taiwanese standard, while other regions (Mainland China, Hong Kong, Korea, and Japan) use「土」.
The decomposition listed on that page is based on the Taiwanese standard, but the handwriting animation is based on the Mainland Chinese standard. If you're not learning Chinese from specifically Taiwan, write it with「土」.
I can't locate the exact source, but the general idea was that Taiwan changed it to「士」(shì) to give a phonetic hint to「寺」(sì).
For reference, the original structure of「寺」(Zhengzhang Old Chinese reconstruction: /*ljɯs/) was from semantic「又」(hand) and phonetic「之/㞢/𡳿」(/*tjɯ/). The word represented by this character is now written as「持」(to support, emphasised through the addition of another hand「扌」).
Free web resources may generally not be consistent between standards when listing this sort of information.