「ボウル」("bowl") is still often written 「ボール」 as very few people (loanword pronunciation nazzi types), actually pronounce the two differently. 「ボウル」 is pronounced 「ボール」 by the rest of the nation.

(I never even knew that a sound like 「オウ」 existed in this world until I started learning English in junior high school. I am sure you have heard Japanese-speakers pronounce "Oh, no!" as 「オーノー」.)

One major reason that some prefer the spelling 「ボウル」 would be that 「ボール」 is already reserved for "ball". The former would just look a bit cooler to certain people, but as native Japanese-speakers, we all know that to pronounce 「ボウル」 in 3 syllables is highly counterintitive. It will simply make you stick out in the Japanese-speaking world.

「ボウル」("bowl") is still often written 「ボール」 as very few people (loanword pronunciation nazi types), actually pronounce the two differently. 「ボウル」 is pronounced 「ボール」 by the rest of the nation.

(I never even knew that a sound like 「オウ」 existed in this world until I started learning English in junior high school. I am sure you have heard Japanese-speakers pronounce "Oh, no!" as 「オーノー」.)

One major reason that some prefer the spelling 「ボウル」 would be that 「ボール」 is already reserved for "ball". The former would just look a bit cooler to certain people, but as native Japanese-speakers, we all know that to pronounce 「ボウル」 in 3 syllables is highly counterintuitive. It will simply make you stick out in the Japanese-speaking world.