What benefit would that be outside of linguistics?

It helps with translation, with knowing the origin of a word, with having a general idea how to pronounce something, etc. Fundamentally, it comes down to "if it ain't broke, don't fix it". Those letters in that order can have that pronunciation in English, so why change the spelling from the origin language if you don't have to?

But isn't it a major benefit that it's spelt like the Latin root?

If it were "cella", then maybe. But, even then, probably not. The main senses in which "cell" are used now are only indirectly related to the original word. "cella" meant a small room, or hut. It didn't mean a room in a prison or a small biological unit. It's a word with a different meaning with different spelling. It's not really worth keeping some of the letters from the original spelling for a completely different meaning, especially because the letter "c" is so bad when it comes to confusion between the "c" and "k" sounds.

Basically, it comes to the idea that if you're going to address issues in the spelling, they should be the "worst offenders", otherwise changing the spelling causes disruption for no real benefit. They should be the letters or sequences of letters that are hardest for English learners to understand.

I don't think the "o" vs "ou" in words like "colour" are even in the top 50 of those, whereas the "c" being used as a /k/ sound in colour is another matter.