ERP systems typically don't fail because of their databases or frontends(and, when they do, they tend to be big, huge, must-talk-to-all-the-legacy-systems-and-support-analysis-and-reporting-at-nontrivial-scale situations that isn't a trivial matter to handle with just some basic web experience). They fail because the process of capturing(and where necessary taking a hard look at and changing) all the business processes so that the dev side can implement them or make sure that they are handled by the product they've chosen is ugly and complex.
Similarly; nobody picks excel because of confusion about its power and capabilities: overwrought-but-inadequate excel is what happens when there is no effort, or no successful one, to get business practices codified into requirements that can be shoved over to the devs and implemented; so you get ad-hoc development of local bandaid tools; typically bolted together by a fair amount of manual copy-paste and futzing; implemented in whatever the people who are familiar with the processes are familiar with. Not uncommonly excel ends up being that; as it's at a pretty favorable intersection between "power" and "number of basically nontechnical users at least partially qualified to work with it".