I seem to recall that the place where you are uploading your images has a quite small file size limit. If you'd like us to look at a file, to find places where you can reduce the size, please share the SVG file.
Assuming the image which is the source of this problem, is to be uploaded to this site, you will definitely want to convert the text to path. Otherwise, as Moini said, if people who either view or download the image don't have that font installed, they won't see that font. They will see whatever font their computer decides to substitute. It might look quite the same, or it might be noticably different.