Wix needs to bring an update because we need H4 and H5 headings at least H4 Google sees H2 and H3 headings as the same and H2 and H3 headings affect SEO more than H4 so when we create a lot of heading we need to put H4 "like in WordPress" please let us able to add H4 headings because we can not create good contents like that it's not just about SEO it's also about design H2 and H3 headings are big styles (I know I can edit it but I don't want to because I use it also in my website design) we need small headings like H4 and H5 please let us able to add H4 headings!!
Look at the example I added a H2 heading but H3 heading is almost the same because it's big even if I make it smaller from the Editor doesn't matter it will affect to SEO different than H4 Wix should think about "You Deserve Better Ads" again because Wix talks about WordPress but Wix doesn't even has the H4 heading option in Wix Blog app xd.

Hey @ExWeiv, we are working on it! We can't disclose the ETA but it's in the progress.