Making maps is something everyone does and existing map software is really targeted to professionals. Even if you figure out how to make a map with the GIS desktop software (QGIS or ESRI), taking the maps you made and putting them online is another huge hurdle that requires a separate skillset.

I think Felt is taking the winning approach - to enlarge the market by making map making possible for everyone and making it be online-first.

I've been playing with https://clockworkmicro.com/ to make layers in my spatial database viewable by others, but it requires some GIS knowledge and familiarity with databases (unlike Felt).