Something else to consider is that different e-chart makers have licensed proprietary data. Don't know if it has changed now, but Garmin had licensed the Explorer Charts data for the Bahamas which is superb and Navionics had not. So Garmin is (was?) the way to go in the Bahamas.
In the Eastern Caribbean, Navionics had licensed the Imray/Iolaire data so they had the upper hand there.
It is interesting when the paper chart debate happens that people go on at length about how wonderful and accurate paper charts are. I get a sense that they have not been off the beaten track where you get paper charts like the one on the left. In more remote areas, hydrographers focussed on areas that were of interest to navies and commercial shipping and had little interest in the shallow little bays that are interest to sailors. We anchored in a bay in southern Indonesia that was about a mile across. There was one sounding in the middle that was something like 7m. That seemed pretty good so we went for it while keeping a close eye on the sounder. When we got there it was about 12 m deep. We kept heading towards shore for a quarter mile or so until we got to 5 m or thereabouts. In another place we were anchored a couple of hundred metres on land. When we left in the morning, we were in water too deep for the sounder but still on land according to the chart. Much of the world has not been surveyed.