I've heard many different reasons for this but what do you think??

They both are European vocalists, both more or less fall into the Alternative genre & generally have unique styles.

Adele is not that alternative, that's why she succed in the way she did. She has a good voice, good melodies and love/break up songs. The perfect pack for the general public.

I think they see Florence more like a hipster singer or something, she has good songs, don't get why she hasn't got enough success.

They aren't even that similar...

She is too good for the general public.

adele is safe, florence isnt. easy

I've asked this same question before.

Adele's more commercial. She's not alternative she is soul pop. Florence draws influence from art rock, soul, and bjork. She just isn't the kind of person to be a superstar.

Florence's music has no pop or radio appeal.

Adele is marketed much better,her music got poppier on "21".Florence's music isn't made for huge mass appeal.

To put it bluntly, because Adele is younger and overweight, hence making her much more accessible to the masses. Adele's material is easier to relate to. 21 was a conscious effort to please the masses.

I don't know. I guess Florence is just too good for the general public...

I stated the similarities in the OP. I never said they were the same.

Then why wasnt 19 a huge smash? The songs were just as relateable

I have seen a lot of serious music fans about compare them both and calling them ''soul'' artists.

I never said that you did. I said that they aren't that similar. Besides them both being from the UK, I don't see the similarities. Just because they are both from the same country doesn't mean they should have similar success.

Florence is more alternative/rock, whereas Adele's music has more crossover and AC appeal.

It aint that easy. That way every young over weight girl would be selling 20+ Million.
And 19 was also quite successful. Got her 2 grammys.

+1

It wasn't commercial enough."21" is poppier and that's why it has much bigger appeal to general public.