Hi The_brooke,
No … it would be softer and more conforming than the floor … although it would probably be too firm for most (but not all) people.
Your own personal testing or sleeping experience is really the only way to know how each combination of ILD’s will feel for you. I would also keep in mind that every layer or component in a mattress will affect the feel and performance of every other layer and the mattress as a whole and ILD by itself (particularly of only single layers) isn’t the only spec that makes a difference in either the softness or performance of a material (see post #4 here).
If you aren’t able to test some different combinations of latex in person (which I would strongly encourage even if it’s not the same as what you plan to order so that you have a sense of the “feel” of latex) then the “best” way to choose would be a more detailed conversation with an experienced and knowledgeable manufacturer who can use their knowledge to help you choose based on the information you provide and the “averages” of their customers that are similar to you (see mattress firmness/comfort levels in post #2 here and post #2 here). This would give you a starting point and from there (assuming you have exchangeable layers) you could do more fine tuning by rearranging or exchanging layers based on your actual sleeping experience.
I’m not sure what your current status is with your mattress or if you are asking because you are considering either a topper or a different mattress but there are also some topper guidelines in post #2 here and the posts it links to that may also be useful if that’s a direction you are considering (although a topper is better suited to softening up a mattress that is too firm than making a mattress that is too soft any firmer).
Phoenix