Hi Eyal,
I can only speak from my personal experience as a business and domestic user of Base.
I’ve been using the various iterations of Base since StarOffice days. It has always lacked the polish of its main rival MS Access, and for those on macOS, Filemaker Pro, making sophisticated UI interaction a challenge well beyond the realms of what a common user might be comfortable with. Even the signifcant developer investment brought in by Sun with the Java embedded database of hsqldb 1.8 and the Pentaho report builder integration only relatively improved that experience. The fact remains that Base development has always been the unloved child of the LibreOffice project. Maintenance of the codebase has always seemed to play second fiddle to other modules, where changes made to Writer or Calc have been considered priority topics to the detriment of bugs that were then created in the Base codebase.
From recollection, when metrics were being taken of the use of LibreOffice, Base was specifically excluded. Why exactly that was the case, I don’t know. Perhaps there have been more recent metrics taken that do include Base statistics.
From an ecosystem partner point of view, it would appear that Base was considered for quite long time as a black hole that wasn’t worth the time and significant investment for any reasonable ROI in a decent timeframe. Yes, there was the embedded Firebird migration project, but that literally didn’t even make it halfway to being a replacement for the current and now somewhat ancient hsqldb embedded variant.
Additionally, it is of note that none of the online versions of LibreOffice of which I’m aware (and unless I’ve missed something), have any sort of Base component. This appears to have been a deliberate choice by the ecosystem partners.
With regard to MS Access, it is my understanding that it is not included in the default domestic subscription model of Microsoft 365 and that it is only available separately for Windows PC as a desktop application. This means that most domestic users are shut out from Access. An improved LO Base module would go a long way to opening up that area to people looking for a way to find the same thing without being platform restricted and having to pay separately for it. Similarly on Mac, FMPro is only available through payment of a fairly costly license fee.
It seems to be fairly difficult at the moment to find any multi-OS compatible database application or portable database solution that has a fairly easy to use UI. Either any such solutions require an embedded JVM (or corresponding JRE/JDK at corresponding system level), or else a complete Java application with the inherent limitations of the Swing UI, or else the proposed solutions are not multi-OS nor multi-arch.
Having a modern, functional Base module with a reporting engine not reliant on Java and multi-OS, multi-arch to boot, would go a long way to filling that need and helping to democratise the use of LibreOffice even further.